fix(custom-model): guard, document and test the session-supplied dsh home

Second review round on PR #755: skip non-absolute DSH_HOME candidates so a relative home can never mkdir under the server cwd; probe a session-supplied home with probePathKind in both async routes before the synchronous apply; test the session env-override lookup (seventh arg) incl. the self-link fall-through and the relative-home skip; reject '.' and '..' as realHomeFallback and enforce linkFromRealHomeDirs subset in the schema; fix the stale apply JSDoc and the two doc lines lagging the verified dsh run; state the shared/isolated split plainly.

docs/architecture-invariants.md

@@ -634,7 +634,7 @@ Adding the header changed the preamble, so `CODEMAN_PREAMBLE` was bumped (1.22.0
 
 ⚠️ **Security**: every env var this feature can redirect (`ANTHROPIC_BASE_URL`, `GOOGLE_GEMINI_BASE_URL`, `CODEX_HOME`, `GROK_HOME`, `HOME` for pi/omp, `OPENCODE_CONFIG_CONTENT`, etc.) is in that CLI's `privilegedEnvKeys` — several of these were reachable via the generic `envOverrides` field's prefix allowlist BEFORE this feature existed (the env allowlist is global and prefix-based, not per-CLI-scoped), so building this surfaced and closed a pre-existing gap rather than opening a new one. `ANTHROPIC_*` is deliberately NOT in claude's `allowedPrefixes` at all — Anthropic-traffic redirection can only happen through this feature's own admin-configured, SSRF-guarded route, never a plain client-supplied `envOverrides`.
 
-**Confidence, verified end-to-end against a real llama-swap server via the DYNAMIC `scripts/test-local-llm-harnesses.ts`** (reads the live CLI registry, so a registry change needs zero script edits): claude/opencode/pi/grok/omp **PASS**; codex config structure is correct, and codex only speaks the Responses API since Feb 2026 (`wire_api = "responses"`) — re-verified live against a llama-swap deployment that DOES answer `/v1/responses` (an earlier test's harder failure against a different deployment does not reproduce everywhere): a plain, no-tool-call chat turn gets a real reply, but a real tool-call attempt came back as `agent_message` TEXT (the tool-call JSON printed as the answer) rather than an executable `function_call` item — confirmed via `codex exec --json`'s raw event stream. Tool execution is what makes codex a coding agent, so it remains not usable for real work either way, just with a more precise failure mode than a flat protocol break; gemini fails with `Invalid auth method selected` (an undocumented `GATEWAY` AuthType gemini-cli selects once `GOOGLE_GEMINI_BASE_URL` is set — unresolved after real investigation); deepseek's originally-reported `HTTP_404` is root-caused and fixed — its bundled `@deepseek-ai/dsh-llm-deepseek` module builds `${DEEPSEEK_BASE_URL}/chat/completions` with no `/v1` of its own (confirmed by installing the real package and reading its source), live against llama-swap (`.../chat/completions` 404s, `.../v1/chat/completions` succeeds) — and the env-var redirect that first fixed it has since been REPLACED by a `configDir` recipe: a per-session `DSH_HOME` carrying only a generated `cordis.patch.yml` that declares a `codeman-custom` `openai-completions` provider over the installed profile, with the `/v1` fix living in `renderConfigFile`'s shared `withV1Suffix()` (every file template applies it; the `env` kind's `appendV1Suffix` flag now belongs to copilot alone) and the session's state symlinked back from the real dsh home; a real "hello world" reply through an actual `dsh` binary is still outstanding before calling this fully verified like the harnesses above; antigravity has no known mechanism at all. See the confidence table in `docs/custom-model-endpoints-plan.md` for the full detail on each.
+**Confidence, verified end-to-end against a real llama-swap server via the DYNAMIC `scripts/test-local-llm-harnesses.ts`** (reads the live CLI registry, so a registry change needs zero script edits): claude/opencode/pi/grok/omp **PASS**; codex config structure is correct, and codex only speaks the Responses API since Feb 2026 (`wire_api = "responses"`) — re-verified live against a llama-swap deployment that DOES answer `/v1/responses` (an earlier test's harder failure against a different deployment does not reproduce everywhere): a plain, no-tool-call chat turn gets a real reply, but a real tool-call attempt came back as `agent_message` TEXT (the tool-call JSON printed as the answer) rather than an executable `function_call` item — confirmed via `codex exec --json`'s raw event stream. Tool execution is what makes codex a coding agent, so it remains not usable for real work either way, just with a more precise failure mode than a flat protocol break; gemini fails with `Invalid auth method selected` (an undocumented `GATEWAY` AuthType gemini-cli selects once `GOOGLE_GEMINI_BASE_URL` is set — unresolved after real investigation); deepseek's originally-reported `HTTP_404` is root-caused and fixed — its bundled `@deepseek-ai/dsh-llm-deepseek` module builds `${DEEPSEEK_BASE_URL}/chat/completions` with no `/v1` of its own (confirmed by installing the real package and reading its source), live against llama-swap (`.../chat/completions` 404s, `.../v1/chat/completions` succeeds) — and the env-var redirect that first fixed it has since been REPLACED by a `configDir` recipe: a per-session `DSH_HOME` carrying only a generated `cordis.patch.yml` that declares a `codeman-custom` `openai-completions` provider over the installed profile, with the `/v1` fix living in `renderConfigFile`'s shared `withV1Suffix()` (every file template applies it; the `env` kind's `appendV1Suffix` flag now belongs to copilot alone) and the session's state symlinked back from the real dsh home; a real "hello world" reply through an actual `dsh` binary has since been verified live by the maintainer (dsh 0.1.1-rc.2, dsh-TUI 0.10.0-beta.1: `--dump-config` shows the patched rows, the TUI boots on the chosen model, and a prompt reaches the endpoint as `POST /v1/chat/completions` with the reply rendering in the TUI), so this is verified end-to-end like the harnesses above; antigravity has no known mechanism at all. See the confidence table in `docs/custom-model-endpoints-plan.md` for the full detail on each.
 
 ⚠️ **The Run-menu picker generates entries from `window.__codemanCustomModelClis`** (`server.ts`, injected at page render from `enabledClis().filter(kind==='agent' && customModelInjection.kind!=='unsupported')`, JSON-escaped against a literal `</script>` via the exported `escapeScriptJson()` since `label` is a user-`clis.json`-settable string unlike the neighbouring booleans-only `__codemanCliAvailable`), never a hardcoded per-CLI id list in the frontend — the same "no branching on CLI id outside stock.ts" discipline the registry itself enforces. One entry per (capable, INSTALLED CLI, saved endpoint) pair, e.g. "Claude Code (llama.cpp)", filtered through `isCliAvailable()` like the stock entries. Clicking one calls `selectCustomModelEntry(mode, endpointId)` (`session-ui.js`), which re-fetches the endpoint (never trusts anything cached from the dropdown's render — the 5-minute sweep below or a settings edit may have changed it since) and decides the model: exactly one discovered model launches straight away, two or more open `#customModelPickModal` to ask, with `defaultModelId` marked but never auto-chosen (asking exists so ONE launch can deliberately differ from the saved default).
 

docs/custom-model-endpoints.md

@@ -558,16 +558,18 @@ for '<id>' not found. Defaulting to fallback metadata...` on launch —
   chosen model, and a prompt reaches the endpoint as
   `POST /v1/chat/completions` with the right model, the bearer key and
   `max_tokens: 8192`; the reply renders and the context window shows in
-  the footer. What such a session SHARES with the real home is exactly
-  the linked entries — `profiles/`, `sessions/`, `settings.yaml`.
-  Everything else in the generated `DSH_HOME` stays isolated:
-  `storages/` (dsh-TUI's persisted `/model` choice and workspace
-  state), `.agent-presets` and `.env`. Whether those dotted ones should
-  be shared too is an open design question left to the maintainer —
-  linking them additionally needs `homeSegmentName` to allow a leading
-  dot. Note too that the generated home-level patch row REPLACES the
-  `dsh-tui` row's whole `config` for the session, so a profile-level
-  `effort`/`preset` does not apply.
+  the footer. What such a session SHARES with the real home is
+  exactly the linked entries — `profiles/`, `sessions/`,
+  `settings.yaml`. Everything else in the generated `DSH_HOME` is
+  isolated: `storages/` (dsh-TUI's persisted `/model` choice and
+  workspace state), `.agent-presets` and `.env`. Two consequences of
+  the generated home-level file follow: the user's own home-level
+  `cordis.patch.yml` does NOT apply in such a session (the generated
+  file replaces it; profile-level patch files reached through the
+  linked `profiles/` still compose), and the generated patch REPLACES
+  the `llm-pi-ai` provider row's whole `config` for the session. Note
+  too that it likewise REPLACES the `dsh-tui` row's whole `config`, so
+  a profile-level `effort`/`preset` does not apply.
 - **Antigravity** — no known custom-endpoint mechanism at all; unsupported.
 
 See the confidence table in `custom-model-endpoints-plan.md` for the full detail behind

docs/wiki/Custom-Model-Endpoints.md

@@ -186,7 +186,7 @@ read is treated as one slot, never guessed.
 | **Claude Code, opencode, Pi, Grok, OMP** | Verified end-to-end against a real local server.                                                                                                                                                                     |
 | **Codex**                                | Config is correct, and plain chat can work against a server that speaks the Responses API — but a real tool-call attempt comes back as inert text instead of running, so it's still not usable for real coding work. |
 | **Gemini**                               | Fails with an auth error gemini-cli raises once redirected. Unresolved; don't rely on it yet.                                                                                                                        |
-| **DeepSeek**                             | The original 404 is root-caused and fixed (DeepSeek Harness's own code was missing a `/v1` most local servers require) — not yet re-run against a real `dsh` install to confirm end-to-end.                          |
+| **DeepSeek**                             | Verified end-to-end against a real `dsh` install (dsh 0.1.1-rc.2, dsh-TUI 0.10.0-beta.1): the original 404 is root-caused and fixed, and the redirect is now a generated per-session patch file whose prompt reaches the endpoint as `POST /v1/chat/completions`.                          |
 | **Antigravity**                          | No known custom-endpoint mechanism at all. Not offered.                                                                                                                                                              |
 
 Which harnesses show up in the Run-menu picker is read live off Codeman's own CLI registry,