fix(terminal): strip opencode's mouse DECSETs so a drag selects text again

opencode's TUI enables mouse tracking. tmux runs with `mouse off`, so it passes
the PANE's DECSETs straight through to the tmux client, and the browser's xterm
obeyed them: `mouseTrackingMode` flipped to 'any' (measured 62 none / 18 any over
16s) and xterm then reported DRAGS to the TUI instead of selecting locally.

In that state marking text produced no selection at all, so copy-on-select
silently did nothing (5/5 dead drags while `any`), and the obvious fallback —
Ctrl+C — is opencode's `app_exit`, which ended the session. Both were hit here.

opencode needs the middle strip: alt-screen toggles AND mouse DECSETs, but NOT
`3J` (a TUI is not a `clear` consumer). That is `altScreen: 'strip-mux-and-mouse'`
+ `isMuxMouseStripMode`, applied to the live stream (session.ts) and the replay
of a stored buffer, now the exported `stripReplayBuffer()` (session-routes.ts).

The browser's mouse-report gate keeps no mode list any more:
`_shouldReportMouseToCli()` reads only `cliMouseTracking`. The server sets that
flag solely in the mouse-strip branch (`_recordStrippedMouseMode`, one caller),
so it can only be true for a mode whose DECSETs are stripped, and whichever modes
the registry strips, the browser follows. Clicks still reach opencode through the
hand-encoded SGR tap it gates.

The `altScreen` JSDoc gets the decision table its three independent choices need
(alt-screen / `3J` / mouse DECSETs), written from the predicates, including that
`preserve` and `strip-mux-only` take the same runtime row. The table is pinned for
every stock CLI, with and without tmux, on both the live strip and the replay
strip, plus the published flag (test/claude-scrollback-strip.test.ts), so the two
halves cannot drift and a mis-ordered replay branch fails.

Docs and comments that still said opencode keeps its mouse reporting or gets the
narrow strip are updated (CLAUDE.md, architecture-invariants, scrollback and
copy-shortcut plans, session.ts, terminal-ui.js).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/architecture-invariants.md

@@ -37,7 +37,7 @@ Pure helpers unit-tested in `test/base-path.test.ts` + `test/webview-proxy.test.
 
 ### External CLI modes (OpenCode, Codex, Gemini, Antigravity, Pi, Grok, DeepSeek, OMP)
 
-**External CLI modes (OpenCode, Codex, Gemini, Antigravity, Pi, Grok, DeepSeek, OMP)**: `isExternalCliMode()` in `session.ts` (`mode === 'opencode' || 'codex' || 'gemini' || 'antigravity' || 'pi' || 'grok' || 'deepseek'`) gates Claude-specific behavior — Ralph tracker, BashToolParser, token/CLI-info parsing, and ❯-prompt readiness detection are all skipped (these CLIs render their own TUIs; readiness = output stabilization instead). ⚠️ **Work detection left this gate in #385** and is now per-CLI `capabilities.workDetect` data (`promptGlyph` + `workingLine`), because gating it on the mode left every Codex session reporting `idle` for its entire life; a CLI declaring neither falls back to Claude's pair, which is logic-identical to the pre-registry behaviour. All seven modes **require tmux — no direct PTY fallback** — because secrets are injected via `tmux setenv` (socket-scoped `${this.tmux()} setenv`, never on the spawn command line): OpenCode gets `OPENCODE_CONFIG_CONTENT` etc., Codex gets `OPENAI_API_KEY`/`CODEX_API_KEY`/`CODEX_HOME` (`setCodexEnvVars`), Gemini gets `GEMINI_API_KEY`/`GOOGLE_API_KEY`/`GOOGLE_CLOUD_PROJECT`/`GOOGLE_APPLICATION_CREDENTIALS`/`GOOGLE_GENAI_USE_VERTEXAI` etc. (`setGeminiEnvVars`, all in `tmux-manager.ts`). Codex specifics: command built by `buildCodexCommand()` (`--model`, `--config model_reasoning_effort=<level>` from `reasoningEffort`, `--config tui.animations=<bool>` from `animations`, `resume <id>`, `--dangerously-bypass-approvals-and-sandbox` from the `codexConfig` payload / `codexDangerouslyBypassApprovals` app setting; `renderMode` is schema-coerced to `'hybrid'`, the only supported mode). Gemini specifics: command built by `buildGeminiCommand()` (`--skip-trust` always, `--approval-mode <default|auto_edit|yolo|plan>` defaulting to `yolo` for parity with Claude's `--dangerously-skip-permissions`, `--model`, `--resume` from the `geminiConfig` payload); availability via `GET /api/gemini/status` — session/quick-start routes fail with `OPERATION_FAILED` + install hint (`npm install -g @google/gemini-cli`) when missing. Codex, Gemini, Antigravity, Pi, Grok, DeepSeek and OMP export `COLORTERM=truecolor` and unset `NO_COLOR`; `opencode` unsets `COLORTERM`. **Terminal colour env** under Session launch modes covers Claude and says which panes those declarations actually reach. Gemini joins `isAltScreenStripMode()` (Codex/Claude/Gemini are Ink TUIs that repaint inline → strip alt-screen/`3J` so scrollback survives). Codex availability via `GET /api/codex/status`. Antigravity specifics: command built by `buildAntigravityCommand()` (`--model`, `--conversation <id>` resume, `--dangerously-skip-permissions` from the `antigravityConfig` payload); availability via `GET /api/antigravity/status` — routes fail with `OPERATION_FAILED` + install hint (`curl -fsSL https://antigravity.google/cli/install.sh | bash`) when missing. Unlike the other three it is NOT an npm package (standalone binary, `~/.local/bin/agy`), which is why `docker/agent.Dockerfile` installs it with its own `--dir /usr/local/bin` step rather than in the `npm install -g` line, and why it does NOT join `isAltScreenStripMode()`. Frontend: run-mode dropdown → `runCodex()`/`runGemini()` in `session-ui.js` ("Run CX"/"Run GM" labels), App Settings → Agents & CLIs → Codex; Respawn/Ralph options are Claude-only, so session options open on the Session tab for external CLI sessions. ⚠️ `run*()` MUST unwrap the `{success,data}` envelope (`(await res.json()).data.available` / `data.data.sessionId`) — reading the raw shape silently breaks the run. Tests: `test/run-mode-ui.test.ts` + `test/gemini-mode.test.ts` (vm-sandbox harness, no real DOM). Grok specifics: command built by `buildGrokCommand()` (`--always-approve` from `grokConfig.alwaysApprove` — grok's `bypassPermissions` permission mode, deny rules still apply; `--model`; `--resume <id>` / `--continue`, id-regexed so grok's resume-by-TITLE feature can never put an arbitrary string on the spawn line); availability via `GET /api/grok/status`, which carries `version` because the resolver version-probes candidates (`grok` has npm squatters, e.g. @vibe-kit/grok-cli — `GROK_VERSION_REGEX` is shared with the dependency registry so doctor and run mode agree). Like antigravity it is a standalone binary (xAI installer → `~/.grok/bin`, symlinked into `~/.local/bin`), so `docker/agent.Dockerfile` installs it in its own step (copy to `/usr/local/bin`, drop root's `~/.grok` in the same layer) and it stays OUT of `isAltScreenStripMode()` (fullscreen alt-screen TUI with mouse support — the opencode case, not the Ink case). Env allowlist: `GROK_*` plus the vendor namespace `XAI_*` (`XAI_API_KEY` is grok's documented headless auth var — the same narrow-vendor-namespace reasoning as `GOOGLE_*` for gemini). Docker cred seeding is per-file (`auth.json`, `config.toml`, `pager.toml` from `~/.grok` — the dir also holds `sessions/`, `memory/`, and the ~160MB binaryLine truncated
+**External CLI modes (OpenCode, Codex, Gemini, Antigravity, Pi, Grok, DeepSeek, OMP)**: `isExternalCliMode()` in `session.ts` (`mode === 'opencode' || 'codex' || 'gemini' || 'antigravity' || 'pi' || 'grok' || 'deepseek'`) gates Claude-specific behavior — Ralph tracker, BashToolParser, token/CLI-info parsing, and ❯-prompt readiness detection are all skipped (these CLIs render their own TUIs; readiness = output stabilization instead). ⚠️ **Work detection left this gate in #385** and is now per-CLI `capabilities.workDetect` data (`promptGlyph` + `workingLine`), because gating it on the mode left every Codex session reporting `idle` for its entire life; a CLI declaring neither falls back to Claude's pair, which is logic-identical to the pre-registry behaviour. All seven modes **require tmux — no direct PTY fallback** — because secrets are injected via `tmux setenv` (socket-scoped `${this.tmux()} setenv`, never on the spawn command line): OpenCode gets `OPENCODE_CONFIG_CONTENT` etc., Codex gets `OPENAI_API_KEY`/`CODEX_API_KEY`/`CODEX_HOME` (`setCodexEnvVars`), Gemini gets `GEMINI_API_KEY`/`GOOGLE_API_KEY`/`GOOGLE_CLOUD_PROJECT`/`GOOGLE_APPLICATION_CREDENTIALS`/`GOOGLE_GENAI_USE_VERTEXAI` etc. (`setGeminiEnvVars`, all in `tmux-manager.ts`). Codex specifics: command built by `buildCodexCommand()` (`--model`, `--config model_reasoning_effort=<level>` from `reasoningEffort`, `--config tui.animations=<bool>` from `animations`, `resume <id>`, `--dangerously-bypass-approvals-and-sandbox` from the `codexConfig` payload / `codexDangerouslyBypassApprovals` app setting; `renderMode` is schema-coerced to `'hybrid'`, the only supported mode). Gemini specifics: command built by `buildGeminiCommand()` (`--skip-trust` always, `--approval-mode <default|auto_edit|yolo|plan>` defaulting to `yolo` for parity with Claude's `--dangerously-skip-permissions`, `--model`, `--resume` from the `geminiConfig` payload); availability via `GET /api/gemini/status` — session/quick-start routes fail with `OPERATION_FAILED` + install hint (`npm install -g @google/gemini-cli`) when missing. Codex, Gemini, Antigravity, Pi, Grok, DeepSeek and OMP export `COLORTERM=truecolor` and unset `NO_COLOR`; `opencode` unsets `COLORTERM`. **Terminal colour env** under Session launch modes covers Claude and says which panes those declarations actually reach. Gemini joins `isAltScreenStripMode()` (Codex/Claude/Gemini are Ink TUIs that repaint inline → strip alt-screen/`3J` so scrollback survives). Codex availability via `GET /api/codex/status`. Antigravity specifics: command built by `buildAntigravityCommand()` (`--model`, `--conversation <id>` resume, `--dangerously-skip-permissions` from the `antigravityConfig` payload); availability via `GET /api/antigravity/status` — routes fail with `OPERATION_FAILED` + install hint (`curl -fsSL https://antigravity.google/cli/install.sh | bash`) when missing. Unlike the other three it is NOT an npm package (standalone binary, `~/.local/bin/agy`), which is why `docker/agent.Dockerfile` installs it with its own `--dir /usr/local/bin` step rather than in the `npm install -g` line, and why it does NOT join `isAltScreenStripMode()`. Frontend: run-mode dropdown → `runCodex()`/`runGemini()` in `session-ui.js` ("Run CX"/"Run GM" labels), App Settings → Agents & CLIs → Codex; Respawn/Ralph options are Claude-only, so session options open on the Session tab for external CLI sessions. ⚠️ `run*()` MUST unwrap the `{success,data}` envelope (`(await res.json()).data.available` / `data.data.sessionId`) — reading the raw shape silently breaks the run. Tests: `test/run-mode-ui.test.ts` + `test/gemini-mode.test.ts` (vm-sandbox harness, no real DOM). Grok specifics: command built by `buildGrokCommand()` (`--always-approve` from `grokConfig.alwaysApprove` — grok's `bypassPermissions` permission mode, deny rules still apply; `--model`; `--resume <id>` / `--continue`, id-regexed so grok's resume-by-TITLE feature can never put an arbitrary string on the spawn line); availability via `GET /api/grok/status`, which carries `version` because the resolver version-probes candidates (`grok` has npm squatters, e.g. @vibe-kit/grok-cli — `GROK_VERSION_REGEX` is shared with the dependency registry so doctor and run mode agree). Like antigravity it is a standalone binary (xAI installer → `~/.grok/bin`, symlinked into `~/.local/bin`), so `docker/agent.Dockerfile` installs it in its own step (copy to `/usr/local/bin`, drop root's `~/.grok` in the same layer) and it stays OUT of `isAltScreenStripMode()` (fullscreen alt-screen TUI with mouse support — the opencode case, which is now `isMuxMouseStripMode`, not the Ink case). Env allowlist: `GROK_*` plus the vendor namespace `XAI_*` (`XAI_API_KEY` is grok's documented headless auth var — the same narrow-vendor-namespace reasoning as `GOOGLE_*` for gemini). Docker cred seeding is per-file (`auth.json`, `config.toml`, `pager.toml` from `~/.grok` — the dir also holds `sessionsLine truncated
 
 **DeepSeek Harness (`dsh`) specifics** — the mode that breaks three of the assumptions the six above share, so read this before changing anything about it.
 
@@ -55,7 +55,7 @@ Pure helpers unit-tested in `test/base-path.test.ts` + `test/webview-proxy.test.
 
 ⚠️ **The resolver needs the strictest identity probe of any CLI**, because `dsh` is not merely a squattable npm name: Debian ships an unrelated `dsh` (dancer's shell, `apt install dsh`) that would answer a version probe convincingly. `probeDeepSeekVersion()` therefore checks `dsh --help` against `DEEPSEEK_IDENTITY_REGEX` (`DeepSeek Harness`) FIRST and only then reads a version, and `test/deepseek-cli-resolver.test.ts` pins both the rejection and the VITEST hermeticity gate with a real executable fixture. `DEEPSEEK_VERSION_REGEX` keeps the prerelease tail (`0.1.1-rc.2`), since truncating it would report an rc as a release; it is shared with the `dsh` dependency-registry entry so doctor and run mode agree about the version even though the resolver is stricter about identity.
 
-Model is NOT a session field: it is a composition entry in the profile's config tree (`agent-default-model`), configured in `~/.dsh/settings.yaml` + `cordis.patch.yml`, so both create paths deliberately resolve no model for this mode. Env allowlist: `DSH_*` + `DEEPSEEK_*`; provider keys named by a settings-file `apiKeyEnv` stay OUT, which is pi's 34-provider-key problem in a new shape and gets the same answer. Docker seeds `~/.dsh` per-file (`.env`, `settings.yaml`, `cordis.patch.yml`) and the image installs its OWN profile, because `profiles/` is a per-profile `node_modules` tree — host-arch-specific and far too large to copy per container start. Stays OUT of `isAltScreenStripMode()` (third-party fullscreen TUI — the opencode case). ⚠️ `classifyProfile()` reads the profile's BUNDLES, and "unknown means launchable" is deliberate (anyone can publish an app bundle), but it has one knowably-wrong case: `readProfile()` returns an empty bundle list for a `package.json` with no `dsh.profile.bundles`, which made the SHIPPED `web`/`headless` profiles look third-party and launchable. The directory name is therefore consulted as a LAST resort (`STOCK_NON_INTERACTIVE_PROFILES`), after the bundle patterns, so real bundle evidence always wins over a name the user chose. The loose `tui` arm carries word boundaries for the same reason: it decides which profile boots by default, and matching the middle of `intuition` is not a rule anyone could predict. ⚠️ The generated shim is written **temp + rename**, not in place: the TUI can be exec'ing that exact path while an upgraded Codeman refreshes it, and a half-written file is a syntax error the caller then retries four times per state change forever. Bump `SHIM_VERSION` whenever `SHIM_SOURCE` changes, or an existing shim keeps matching the embedded marker and is never refreshed. Availability via `GET /api/deepseek/status`, the widest per-CLI status shape (`available`/`runnable`/`path`/`version`/`dshHome`/`defaultProfile`/`profiles`); `POST /api/deepseek/install-profile` bootstraps a profile and is the only endpoint in Codeman that installs third-party code — regex-confined specifier, argv-array spawn, privileged grant required in multi-user mode, and the held-open request is bounded by a HAND-ROLLED timeout over a `detached: true` process group (negative-pid SIGTERM→SIGKILL, as `runGit()` does in git-clone.ts). ⚠️ Node's own `spawn` `timeout` is NOT enough: a plugin install fans out into package-manager children, the built-in timeout signals only the direct child, and the survivors hold the inherited stdio pipes open so `close` never fires and the request leaks forever. User guide: `docs/deepseek-integration.md`. Tests: `test/deepseek-mode.test.ts`, `test/deepseek-cli-resolver.test.ts`.
+Model is NOT a session field: it is a composition entry in the profile's config tree (`agent-default-model`), configured in `~/.dsh/settings.yaml` + `cordis.patch.yml`, so both create paths deliberately resolve no model for this mode. Env allowlist: `DSH_*` + `DEEPSEEK_*`; provider keys named by a settings-file `apiKeyEnv` stay OUT, which is pi's 34-provider-key problem in a new shape and gets the same answer. Docker seeds `~/.dsh` per-file (`.env`, `settings.yaml`, `cordis.patch.yml`) and the image installs its OWN profile, because `profiles/` is a per-profile `node_modules` tree — host-arch-specific and far too large to copy per container start. Stays OUT of `isAltScreenStripMode()` (third-party fullscreen TUI — the opencode case, i.e. `isMuxMouseStripMode` is the shape to measure here too). ⚠️ `classifyProfile()` reads the profile's BUNDLES, and "unknown means launchable" is deliberate (anyone can publish an app bundle), but it has one knowably-wrong case: `readProfile()` returns an empty bundle list for a `package.json` with no `dsh.profile.bundles`, which made the SHIPPED `web`/`headless` profiles look third-party and launchable. The directory name is therefore consulted as a LAST resort (`STOCK_NON_INTERACTIVE_PROFILES`), after the bundle patterns, so real bundle evidence always wins over a name the user chose. The loose `tui` arm carries word boundaries for the same reason: it decides which profile boots by default, and matching the middle of `intuition` is not a rule anyone could predict. ⚠️ The generated shim is written **temp + rename**, not in place: the TUI can be exec'ing that exact path while an upgraded Codeman refreshes it, and a half-written file is a syntax error the caller then retries four times per state change forever. Bump `SHIM_VERSION` whenever `SHIM_SOURCE` changes, or an existing shim keeps matching the embedded marker and is never refreshed. Availability via `GET /api/deepseek/status`, the widest per-CLI status shape (`available`/`runnable`/`path`/`version`/`dshHome`/`defaultProfile`/`profiles`); `POST /api/deepseek/install-profile` bootstraps a profile and is the only endpoint in Codeman that installs third-party code — regex-confined specifier, argv-array spawn, privileged grant required in multi-user mode, and the held-open request is bounded by a HAND-ROLLED timeout over a `detached: true` process group (negative-pid SIGTERM→SIGKILL, as `runGit()` does in git-clone.ts). ⚠️ Node's own `spawn` `timeout` is NOT enough: a plugin install fans out into package-manager children, the built-in timeout signals only the direct child, and the survivors hold the inherited stdio pipes open so `close` never fires and the request leaks forever. User guide: `docs/deepseek-integration.md`. Tests: `test/deepseek-mode.test.ts`, `test/deepseek-cli-resolver.test.ts`.
 
 **Pi specifics** (#206, `docs/pi-integration.md`): command built by `buildPiCommand()` (`--model` — the only builder whose model regex admits `:` and `/`, for `sonnet:high` and `openai/gpt-4o` — plus `--provider`, `--thinking`, `--session <id>` / `-c`, and the TRI-STATE `--approve`/`--no-approve`). ⚠️ **Pi has no permission prompts and no sandbox**, so there is no `--dangerously-skip-permissions` analog and Codeman must not invent one; the privilege-shaped knob is `approveProjectTrust`, which makes pi LOAD AND EXECUTE repo-local `.pi/extensions` TypeScript and npm-install missing project packages. It therefore joins `clampExternalCliBypassForOwner()`'s **materialize** branch (gemini's, not codex/antigravity's only-if-sent one): an absent config still yields `--no-approve` for a non-granted owner, because pi's own default is an interactive prompt the session user could answer themselves. ⚠️ `--api-key` is NEVER wired — it would put a provider secret on the spawn command line. ⚠️ Pi stays **out** of `isAltScreenStripMode()`: its default TUI renders into the main screen with terminal-owned scrollback (nothing to strip), and since 0.84.0 the user can flip to a fullscreen TUI at runtime via `/settings`, where the alt screen is load-bearing — being out of the list is exactly what makes that switch safe. ⚠️ Only the `PI_*` env prefix was added; pi's ~34 provider keys share no prefix and `ALLOWED_ENV_PREFIXES` is a single GLOBAL list with no mode context, so admitting them would widen the allowlist for every mode at once (a mode-aware allowlist is the tracked follow-up). ⚠️ `pi` is a short, GENERIC binary name, so unlike the sibling resolvers `pi-cli-resolver.ts` sanity-probes `pi --version` (cached, vitest-skipped) and requires semver-shaped output; `GET /api/pi/status` carries `version` on top of the sibling `{available, path}` shape so a misresolution is diagnosable. Local echo: pi lands on the `'buffer'` overlay via the fallthrough in `_updateLocalEchoState` (pinned in `test/local-echo-codex-gating.test.ts`); if pi's live composer turns out to fight it the way codex's did, the fallback is one `'off'` branch. Tests: `test/pi-mode.test.ts`, `test/routes/external-cli-bypass-clamp.test.ts` (first-ever coverage of the clamp).
 
@@ -213,11 +213,11 @@ Further detail: the `<prefix>: <title>` form (`w3-myapp: fix the login redirect`
 
 ### Terminal scrollback: strip flavors and wheel/touch forwarding
 
-**Two strip flavors, one carry** (#205, `session.ts:_handleTerminalOutput`): the FULL strip (`isAltScreenStripMode` = codex/claude/gemini) removes alt-screen toggles, `3J`, and mouse-tracking DECSETs. Every other mode (shell/opencode/antigravity/pi) gets the NARROW strip (`isMuxAltScreenOnlyStripMode`) — alt-screen toggles ONLY — and only when tmux-backed (`useMux`). Rationale: the tmux CLIENT emits `smcup` as its first bytes at attach, before any program runs, parking xterm in the scrollback-less alternate buffer for the whole session (touch scrolling no-ops; xterm's own wheel handler converts the wheel to Up/Down arrows = readline history cycling — both #205 symptoms). tmux never forwards a pane program's alt-screen toggles to its client (it repaints instead; measured — vim/less inside a pane emit zero to the client), so the only thing the narrow strip ever removes is tmux's own smcup. It keeps `3J` (a user's `clear` is a deliberate scrollback wipe) and the mouse DECSETs (tmux passes those through even with `mouse off`; stripping them would break htop/vim mouse support). ⚠️ The `useMux` gate is load-bearing: `startShell()`/`startInteractive()` fall back to a DIRECT PTY when mux creation fails, and there the inner program's own `?1049h` really does reach xterm — stripping it would break vim/less/htop for real. The replay path (`session-routes.ts`, via `session.usesMux`) applies the same narrow branch; the frontend mirror (`_shouldReportMouseToCli()`) stays claude/codex/gemini because only the FULL strip touches mouse DECSETs. The chunk-boundary carry (`_altScreenSeqCarry`) runs for both flavors. Tests: `test/claude-scrollback-strip.test.ts`.
+**Three strip flavors, one carry** (#205, `session.ts:_handleTerminalOutput`): the FULL strip (`isAltScreenStripMode` = codex/claude/gemini) removes alt-screen toggles, `3J`, and mouse-tracking DECSETs. The MOUSE strip (`isMuxMouseStripMode` = opencode) removes alt-screen toggles AND the mouse DECSETs but KEEPS `3J` — the middle case, for a mouse-capable full-screen TUI: its tracking DECSETs reach the browser (tmux `mouse off` passes the pane's modes through to the client), xterm obeys them, and then every DRAG is reported to the TUI instead of selecting text — so mark-and-copy silently did nothing (measured 62 `none` / 18 `any` over 16s, 5/5 dead drags while `any`) and the obvious fallback, Ctrl+C, is opencode's `app_exit`. `3J` stays because a TUI is not a `clear` consumer. Every other mode (shell/antigravity/pi) gets the NARROW strip (`isMuxAltScreenOnlyStripMode`) — alt-screen toggles ONLY — and only when tmux-backed (`useMux`). Rationale: the tmux CLIENT emits `smcup` as its first bytes at attach, before any program runs, parking xterm in the scrollback-less alternate buffer for the whole session (touch scrolling no-ops; xterm's own wheel handler converts the wheel to Up/Down arrows = readline history cycling — both #205 symptoms). tmux never forwards a pane program's alt-screen toggles to its client (it repaints instead; measured — vim/less inside a pane emit zero to the client), so the only thing the narrow strip ever removes is tmux's own smcup. It keeps `3J` (a user's `clear` is a deliberate scrollback wipe) and the mouse DECSETs (tmux passes those through even with `mouse off`; stripping them would break htop/vim mouse support — which is exactly why the mouse strip is opt-in per CLI and not part of the narrow flavour). ⚠️ The `useMux` gate is load-bearing: `startShell()`/`startInteractive()` fall back to a DIRECT PTY when mux creation fails, and there the inner program's own `?1049h` really does reach xterm — stripping it would break vim/less/htop for real. The replay path (`session-routes.ts`, via `session.usesMux`) applies the same three branches; the frontend gate (`_shouldReportMouseToCli()`) keeps no mode list at all: it reads only the published `cliMouseTracking`, which the server sets solely in the mouse-strip branch, so it can only be true for a mode whose DECSETs are stripped — the modes where the browser's hand-encoded tap (`_sendSyntheticSgrTap`) is the only way a click still reaches the CLI. Whichever modes the registry strips, the browser follows (pinned in `test/claude-scrollback-strip.test.ts`). The chunk-boundary carry (`_altScreenSeqCarry`) runs for all three flavors. Tests: `test/claude-scrollback-strip.test.ts`, `test/terminal-touch-tap.test.ts`.
 
 ⚠️ **What the full strip removes, it must REMEMBER.** Stripping the mouse DECSETs means xterm's `modes.mouseTrackingMode` is permanently `'none'` for those modes, so the browser hand-encodes click reports to compensate (`_sendSyntheticSgrTap`). With no state to consult it did that on EVERY click, which delivered mouse reports to programs that never asked for them: the same pane runs a plain shell whenever the CLI has exited or a `shell` was started inside a claude-mode session, and a shell prints the report as literal text (`[<0;88;20M`), garbling the next line typed. `_recordStrippedMouseMode()` therefore records each stripped sequence as it goes and publishes `cliMouseTracking` through `toState()`, and `_shouldReportMouseToCli()` requires it. ⚠️ Only the TRACKING modes count (1000/1001/1002/1003): 1005/1006 select an ENCODING and 1007 is alt-scroll, and counting those would put the stray reports straight back. ⚠️ The change broadcasts IMMEDIATELY rather than through `broadcastSessionStateDebounced`, because the flag flips when a dialog opens and the user can click that dialog inside the 500ms debounce window. Measured on a live claude 2.x: the CLI holds a tracking mode on continuously in fullscreen (so clicks keep being reported exactly as before; the default inline renderer holds none, measured on 2.1.283 even with `/model` open), while a bash prompt in the same stripped mode reports nothing. Fails toward silence: after a server restart the flag is false until the CLI re-emits, which tmux does at client attach.
 
-**Only claude ≥ 2.1.187 with mouse tracking on forwards the wheel; everything else scrolls local scrollback** (#227 follow-up, `terminal-ui.js:_shouldForwardWheelToApp`). Codex was in the forward list until a reporter hit a completely dead wheel in codex tabs while the scrollbar drag worked. Measured against codex-cli 0.147.0 in a bare tmux: it never enables mouse tracking (`mouse_any_flag=0`) and SGR wheel reports fed to its PTY change nothing on screen, because it runs an INLINE viewport (`alternate_on=0`) and pushes its transcript into the terminal's own scrollback (tmux `history_size` grows) instead of paging in-app. So for codex, local scrollback IS the transcript and forwarding swallowed every tick. Claude repeats this exactly in its default INLINE renderer (measured on 2.1.280: `alternate_on=0`, `mouse_any_flag=0`, `history_size` grows), and swipes on iOS Safari were dead there while codex scrolled; only fullscreen claude (`CLAUDE_CODE_NO_FLICKER=1` or `"tui": "fullscreen"` in `~/.claude/settings.json`: alt screen plus modes 1003/1006) pages its transcript on wheel reports. So claude forwards only while the server-observed `cliMouseTracking` flag is true; a stale-false flag after a server restart falls through to the PageUp/PageDown fallback, never a dead wheel. ⚠️ "The TUI is a strip mode" is NOT evidence that it consumes wheel reports — verify with a real `\x1b[<64;c;rM` write into a live pane before adding a mode here. Hand-encoded SGR TAPS are gated by `_shouldReportMouseToCli()` (strip mode AND the server-observed `cliMouseTracking` flag, recorded by `_recordStrippedMouseMode` in session.ts as it strips): codex never enables mouse tracking, so since #325 no tap report is sent there at all — click-to-position was already a measured no-op in codex, and a pane that has fallen back to a shell no longer receives `[<0;88;20M` junk.
+**Only claude ≥ 2.1.187 with mouse tracking on forwards the wheel; everything else scrolls local scrollback** (#227 follow-up, `terminal-ui.js:_shouldForwardWheelToApp`). Codex was in the forward list until a reporter hit a completely dead wheel in codex tabs while the scrollbar drag worked. Measured against codex-cli 0.147.0 in a bare tmux: it never enables mouse tracking (`mouse_any_flag=0`) and SGR wheel reports fed to its PTY change nothing on screen, because it runs an INLINE viewport (`alternate_on=0`) and pushes its transcript into the terminal's own scrollback (tmux `history_size` grows) instead of paging in-app. So for codex, local scrollback IS the transcript and forwarding swallowed every tick. Claude repeats this exactly in its default INLINE renderer (measured on 2.1.280: `alternate_on=0`, `mouse_any_flag=0`, `history_size` grows), and swipes on iOS Safari were dead there while codex scrolled; only fullscreen claude (`CLAUDE_CODE_NO_FLICKER=1` or `"tui": "fullscreen"` in `~/.claude/settings.json`: alt screen plus modes 1003/1006) pages its transcript on wheel reports. So claude forwards only while the server-observed `cliMouseTracking` flag is true; a stale-false flag after a server restart falls through to the PageUp/PageDown fallback, never a dead wheel. ⚠️ "The TUI is a strip mode" is NOT evidence that it consumes wheel reports — verify with a real `\x1b[<64;c;rM` write into a live pane before adding a mode here. Hand-encoded SGR TAPS are gated by `_shouldReportMouseToCli()` (the server-observed `cliMouseTracking` flag, recorded by `_recordStrippedMouseMode` in session.ts as it strips, so only ever true for a stripped mode): codex never enables mouse tracking, so since #325 no tap report is sent there at all — click-to-position was already a measured no-op in codex, and a pane that has fallen back to a shell no longer receives `[<0;88;20M` junk.
 
 **Wheel/touch forwarding is NOT gated on viewport-at-bottom** (#205, `terminal-ui.js:_shouldForwardWheelToApp`): for sessions verified to scroll their own transcript on SGR wheel reports (claude ≥ 2.1.187 while `cliMouseTracking` is true, i.e. fullscreen; version via the local/docker/remote `--version` probes), the plain wheel AND touch drags forward as coalesced SGR reports (`_forwardScrollToApp` → `_sendSyntheticSgrWheel`, 40ms batches, 5-tick cap, 512-byte queue bound). It used to gate on the viewport being at the bottom so both scrollbacks stayed reachable, but a repaint-mode CLI keeps NO terminal scrollback of its own — xterm's buffer holds only replayed repaint frames, so local scrolling drags the CLI's pinned prompt box up the screen over stale frames; and `scrollToLastNonEmptyLine()` routinely parked the viewport off-bottom, silently pinning the wheel to local. Forwarding now snaps the viewport home first (SGR coordinates address the LIVE screen — a report computed from a scrolled-up viewport would hit-test the wrong row). Local scrollback remains on Shift+wheel and the `terminalWheelLocalScrollback` opt-out (both also cover touch via the shared gate; touch has no Shift, so the setting is its only local pin). `_wheelScrollLines()` normalizes `deltaMode` (Firefox fires LINE deltas ≈3/notch — read as pixels that rounded to 0 and fell to the ±1 fallback, ~4× too slow; PAGE deltas scale by `terminal.rows`) while keeping the #154 Shift-axis trap (macOS trackpads put Shift+scroll magnitude on deltaX). Tests: `test/terminal-touch-tap.test.ts`.
 
@@ -674,7 +674,7 @@ Matching semantics: a query containing `/` matches the relative path, otherwise
 2. `copyTerminalSelection` is a registry `action` **deliberately missing from `SHORTCUT_ACTIONS`** (same trick as `command-palette`): the entry stays rebindable and disableable in App Settings, while the generic document-capture loop, which `preventDefault()`s every match it dispatches, skips it and lets the terminal handler decide.
 3. The gate is keydown-only (the custom handler also runs for `keypress`/`keyup`; that is safe here only because xterm drops a Ctrl keypress itself, see the keypress rule above), and `Ctrl+Shift+C` never falls through to the PTY: an "explicit copy" chord that interrupts a running agent because the selection happened to be empty is a footgun with no upside.
 
-Copy goes through `_copyText()` (Clipboard API, then hidden-textarea + `execCommand`), not raw `navigator.clipboard`, because `install.sh`'s LAN option serves plain HTTP where `navigator.clipboard` is undefined; the fallback steals focus, so the terminal is refocused afterwards. Related: xterm registers its own `copy` listener on the terminal element gated on `hasSelection()`, which is why right-click → Copy has always worked. Selection itself is unavailable on touch devices by design (`user-select: none` on the terminal subtree), and in `shell`/`opencode`/`antigravity` tabs the TUI owns the mouse, so selecting there needs Shift+drag. Tests: `test/terminal-copy-selection.test.ts` (gate + wiring invariants), `test/terminal-copy-shortcut.test.ts` (browser, real key presses).
+Copy goes through `_copyText()` (Clipboard API, then hidden-textarea + `execCommand`), not raw `navigator.clipboard`, because `install.sh`'s LAN option serves plain HTTP where `navigator.clipboard` is undefined; the fallback steals focus, so the terminal is refocused afterwards. Related: xterm registers its own `copy` listener on the terminal element gated on `hasSelection()`, which is why right-click → Copy has always worked. Selection itself is unavailable on touch devices by design (`user-select: none` on the terminal subtree), and in `shell`/`antigravity` tabs the TUI owns the mouse, so selecting there needs Shift+drag. `opencode` used to be in that list and no longer is: its mouse DECSETs are stripped server-side (`isMuxMouseStripMode`, see the strip-flavours invariant), so a plain drag selects there. Tests: `test/terminal-copy-selection.test.ts` (gate + wiring invariants), `test/terminal-copy-shortcut.test.ts` (browser, real key presses).
 
 **The main terminal's four copy paths clean the selection first** (`CodemanCopySelection.clean` in constants.js, pure; `cleanedTerminalSelection()` in terminal-ui.js is the half that reads the live terminal). Those four are the `Ctrl+C` chord, right-click, the phone selection button and Auto Copy. ⚠️ Three routes still copy the RAW padded rows, all of them predating the clean: the browser's own Edit → Copy, which xterm's own `copy` listener on the terminal element serves with `selectionText` directly; a `copy-selection` shortcut the user disabled in App Settings, where nothing calls `preventDefault()` and that native listener runs; and the subagent/teammate windows, which build their own `Terminal` in panels-ui.js with no copy wiring at all. xterm hands back whole screen ROWS and its own trim drops only cells that were never written to, so the real spaces a full-screen TUI paints across the unused part of a row count as content and reach the clipboard. Measured against Claude Code in a 282-column pane, single lines arrived carrying 138 trailing spaces on top of the two-space transcript indent. The clean drops each line's trailing run, and strips a LEADING margin when the session's CLI declares one. Four rules keep it honest:
 

docs/scrollback-fix-plan.md

@@ -278,8 +278,8 @@ Touch is always-local by design, and Claude sessions keep content in the normal
 - The `terminalWheelLocalScrollback` opt-out setting keeps working (pins plain wheel to local).
 - The viewport-at-bottom gate stays: once the user scrolled up locally, wheel stays local until they return to bottom.
 - 40ms SGR coalescing: never send per-event writes to the server.
-- Strip parity triangle: `session.ts` live strip ↔ `session-routes.ts` replay strip ↔ `_sessionUsesServerMouseStrip()` in the frontend. If you touch mode lists, update all three.
-- Don't add `opencode`/`antigravity` to any strip/forward list; their TUI wheel behavior is unverified (documented at `_shouldForwardWheelToApp`). ⚠️ 2026-09-16: opencode's half is now MEASURED — 1.18.31 ignores SGR wheel reports but pages its transcript on PageUp/PageDown — so it belongs in the **paging** list (`_localScrollbackIsHollow`), which is not a strip/forward list. antigravity/grok/deepseek/omp remain unverified.
+- Strip parity: `session.ts` live strip ↔ `stripReplayBuffer()` in `session-routes.ts`, both driven by the registry's `altScreen` value and pinned together for every stock CLI in `test/claude-scrollback-strip.test.ts`. The frontend keeps no mode list: `_shouldReportMouseToCli()` reads only the server-published `cliMouseTracking`.
+- Don't add `opencode`/`antigravity` to the wheel-FORWARD list; their TUI wheel behavior is unverified (documented at `_shouldForwardWheelToApp`). ⚠️ 2026-09-16: opencode's half is now MEASURED — 1.18.31 ignores SGR wheel reports but pages its transcript on PageUp/PageDown — so it belongs in the **paging** list (`_localScrollbackIsHollow`). ⚠️ It also joined a STRIP list that same day, for a different reason: `isMuxMouseStripMode` removes its mouse DECSETs so a drag selects text again (see `docs/architecture-invariants.md` §Three strip flavors). antigravity/grok/deepseek/omp remain unverified.
 - The chunk-boundary sequence carry in `_handleTerminalOutput` must not be weakened.
 
 ## Testing (per repo rules)

docs/terminal-copy-shortcut-plan.md

@@ -82,6 +82,7 @@ This is exactly how `command-palette` already behaves: it is a full registry ent
 
 - The server strips mouse-tracking DECSETs for `claude`, `codex`, and `gemini` (`isAltScreenStripMode`, `src/session.ts:179`), which is why plain drag-select works in those tabs even though the TUI has mouse tracking on.
 - `shell`, `opencode`, and `antigravity` keep mouse reporting, so xterm requires `Shift`+drag to force a selection there. Worth one line in the docs, it is not a code change.
+  ⚠️ **Corrected 2026-09-16:** `opencode` no longer keeps mouse reporting in the browser. Its TUI enables tracking DECSETs, tmux `mouse off` passes them through to the tmux client, and xterm then reported DRAGS to the TUI instead of selecting — so `Shift`+drag was the only way to select, and a plain drag silently copied nothing (measured 62 `none` / 18 `any` over 16s; 5/5 dead drags while `any`). The server now strips those DECSETs (`isMuxMouseStripMode`), so a plain drag selects in opencode. `shell` and `antigravity` are unchanged.
 - Touch devices deliberately disable selection entirely (`body.touch-device .terminal-container .xterm{user-select:none !important}`, `styles.css:3196`), and phones have no Ctrl key. This feature is desktop and hardware-keyboard only, with no mobile regression surface.
 
 ### 2.6 Helpers that already exist and should be reused
@@ -245,7 +246,7 @@ The shortcut overlay (`Ctrl+?`) and App Settings -> Shortcuts are registry-drive
 | Whitespace-only or empty selection | `getSelection()` empty string is treated as "no selection", so Ctrl+C still interrupts |
 | macOS Cmd+C | registry treats ctrl/meta as interchangeable, so with a selection it takes our path (same visible result as today's native copy), without one it falls through |
 | Chrome/Firefox `Ctrl+Shift+C` is the devtools inspect chord | browser-level and may still toggle devtools, our copy runs regardless. Document as a caveat, `Ctrl+C` is the primary path |
-| Selection in a tab whose TUI owns the mouse (`shell`/`opencode`/`antigravity`) | unchanged, `Shift`+drag selects, then Ctrl+C copies |
+| Selection in a tab whose TUI owns the mouse (`shell`/`antigravity`; `opencode` left this list on 2026-09-16 — its DECSETs are stripped now) | unchanged, `Shift`+drag selects, then Ctrl+C copies |
 | Web tab (iframe dashboard) focused | xterm handler never runs, browser-native copy inside the iframe |
 | Teammate/subagent terminals (`panels-ui.js:2268`, `onData` wired) | same limitation exists there, out of scope for this PR (section 8) |
 
@@ -281,7 +282,7 @@ Against a throwaway session on the live instance (`curl -sk https://localhost:30
 3. Type a few characters with local echo on (phone or `localEchoEnabled` forced), press Ctrl+C with no selection, confirm buffered text plus interrupt behave as before.
 4. Uncheck the shortcut in App Settings -> Shortcuts, confirm Ctrl+C always interrupts even with a selection.
 5. Rebind it, confirm the new chord copies and Ctrl+C reverts to pure interrupt.
-6. Repeat 1 and 2 in an `opencode` or `shell` tab using Shift+drag to select.
+6. Repeat 1 and 2 in a `shell` or `antigravity` tab using Shift+drag to select (`opencode` selects with a plain drag since 2026-09-16).
 7. Load over plain HTTP (`--host` LAN or `http://127.0.0.1:<port>`) and confirm the `execCommand` fallback copies and focus returns to the terminal.
 8. Mobile smoke: confirm nothing changed (selection is CSS-disabled, no Ctrl key).