fix(terminal): require path labels and preserve markdown context

docs/architecture-invariants.md

@@ -409,7 +409,7 @@ A file path an agent prints is a link on both surfaces it can appear on, and cli
 
 **Path forms beyond the rooted one.** `findFilePathLinks(text)` (constants.js) is the single entry point both consumers call; it reserves spaced candidates first (including unlinkable spans), then detects rooted matches, then `~/` and relative paths (`RELATIVE_FILE_PATH_LINK_PATTERN`, same extension list, pinned equal by `test/link-provider-regex.test.ts`), then folder paths, each only where it overlaps neither an earlier match nor an `http(s)` URL. A relative match must start at a boundary (line start, whitespace, quote, bracket, `=`, `,`, `>`), so it can never begin inside a word, an absolute path or a URL; brackets, `=` and `,` end it (`(shot.png)`, `OUT=shots/a.png`). `resolveLinkedFilePath()` resolves a relative path against the session's `workingDir` (`.`/`..` collapsed, so `../x.png` lands outside and routes like any external path) and passes absolute and `~/` paths through. ⚠️ `~` is the home of the SESSION'S host, which only the server knows: `~/` paths always take the attachment route, where `registerExternalAttachment` expands them (`homedir()` locally, `$HOME` inside the remote probe script), and the guard runs on the expanded, realpath-resolved path as before. ⚠️ Programs hard-wrap their own output short of the terminal edge (Claude Code breaks tool output at 59-118 columns), so xterm's `isWrapped` never fires. `terminalPathLine()` (link provider only; touch selection keeps `terminalLogicalLine`) joins the next row when the previous row ends in a path token with a `/` and no extension and the join reaches an extension; a row that starts a new path is never joined: rooted or `~/`, `./`/`../`, or a relative one that opens on the same top directory the broken token did (the next entry of `git ls-files`/`find`/`ls -R`: `src/components` + `src/index.ts` are two paths, not `src/componentssrc/index.ts`), while a wrapped path continues INSIDE a name, so `…/captures/2` + `026-10-10/…` still joins; a 3+ row chain is kept only if a later row completes the path, and the broken row must be at least as long as the continuing one (keeps `cd /mnt/foo` + a longer next line apart). Tests: `test/file-path-link-forms.test.ts`.
 
-Spaced paths are considered first by `findFilePathLinks()`: accepted candidates reserve their entire span even when unlinkable, so later rooted, relative and folder detectors cannot link fragments. Relative candidates whose first slash-containing word is their last word defer to ordinary detection to exclude list/label prose. This deliberately gives up spaces only in the top directory (`Saved to: 03 Attachments/plan.pptx`); prose shaped like deeper spaced paths (`- Fixed bug in src/My Docs/a.md`, `/home/me/proj contains a.md`) remains ambiguous. Trailing whitespace uses linear `trimEnd()` before the length cap.
+Spaced paths are considered first by `findFilePathLinks()`: accepted candidates reserve their entire span even when unlinkable, so later detectors cannot link fragments. Relative and `~/` spaced paths require an explicit path label (`Path:`, `File:`, `Files:`, `Saved to:`, `Saved as:`, `Wrote:`, `Written to:`, `Output:`, `Created:`, `Location:`, `Attachment:`), optionally preceded by a marker. Generic labels and bare bullets defer to ordinary detection, including slash-containing prose such as `CI/CD` or `45/45`. A later `/`, `~/`, `./` or `../` word starts a separate path; an earlier word ending in `/` is a separate folder. Absolute paths retain own-line and marker forms, including the residual ambiguity `/home/me/proj contains a.md`. The response viewer uses a leading `<strong>` path label in a paragraph or list item as detection context without changing the label or displayed text; paths split across other inline elements remain detected per text node. Tests feed vendored marked output into the jsdom linkifier, so consumed bullets and bold labels are covered. Trailing whitespace uses linear `trimEnd()` before the length cap.
 
 **Folder grid: a folder is granted, then served by bare file name.** A folder path (rooted or `~/` whose last segment has no extension, relative only with a trailing `/`; `FOLDER_PATH_LINK_PATTERN` + `folderLinkPath()`) opens `openFolderGrid()` (panels-ui.js), as does the preview's "Show folder" button. `POST /api/sessions/:id/folders {path}` (`src/folder-listing.ts`) resolves the folder (locally a bounded `probePathKind(…, { pastCap: true })` first, then async `fs.realpath`; remotely one ssh round trip via `remoteListFolder`, through `runWithRemoteSshLimit`), runs the attachment guard on it (blocklist, `confineToWorkspace`, and in multi-user mode `folderAllowedForUser`: a non-admin only inside their own `userSpacePath` or the session's `workingDir`, as the filesystem path picker), locally BEFORE reading it, lists non-hidden subfolders and files of a supported attachment type (each file also blocklist-checked, newest first, capped at `MAX_FOLDER_ENTRIES`), and GRANTS it an id. Files are then fetched as `GET …/folders/:folderId/files/:name/(raw|preview|thumbnail)`: `:name` must be a bare file name of a supported type (no `/`, `\`, NUL, no leading `.`, since the listing hides those), the local file is probed bounded (`unknown` → 503, never 404), and the joined path goes through the SAME `resolveServableAttachmentPath` as an attachment by id (symlink re-resolution, remote re-probe, guard), then the same gate registration applies to what a symlink RESOLVES to (a supported extension on the resolved path and a regular file: locally `fs.stat`, remotely the probe kind; else 400, so `shot.png -> ../secret.bin` is not served and a FIFO or device behind a supported name never reaches `open`), then `folderAllowedForUser` once more on the resolved file, before `serveServableRaw` (the attachment raw route's body, shared) streams it. So browser requests still never carry a path. ⚠️ Grants live in their own registry (`folderGrants`, 32 per session, cleared with the session's attachments), NOT the attachment registry: that one is capped at 200 per session, and paging a folder of 300 renders would evict the session's real attachments. ⚠️ A local folder is never touched unbounded (#516 rule): a folder on a network mount that stopped answering answers 503 with `describeUnknownPath()`, not 404 and not a frozen server. ⚠️ The remote listing script tells "missing" (`E|n`, 404) from "is a file" (`E|f`, 400 `Not a folder`), because the client falls back to the file preview on `Not a folder`; a remote extensionless file otherwise answered "Folder not found". ⚠️ `.folder-grid-overlay` sits at `z-index: 5090`, one step BELOW the preview (5100) and above the response viewer (5000): a tile's preview opens on top and closing it lands back on the grid. ⚠️ ←/→/Esc are handled in a document CAPTURE listener with `stopPropagation`, because the terminal keeps keyboard focus under the overlays and an arrow that reached xterm would be typed into the session; inputs other than xterm's helper textarea keep their keys. ⚠️ A route PARAMETER is capped by the router (Fastify's default is 100 characters, answered as 404 "Route not found"), and a file name goes up to 255, percent-encoded: the server sets `routerOptions.maxParamLength` to `MAX_ROUTE_PARAM_LENGTH` (route-helpers.ts), the route test harness uses the same constant, and a wiring guard pins it. ⚠️ `~/` in a Docker case is refused with 400 (attachment POST and `POST …/folders`): the session is local for these routes, but `~` inside the container is the container's own home, and expanding it on the host would open a different file than the one the agent printed. Tests: `test/routes/folder-grid-routes.test.ts` (incl. the listing script on a real `sh`), `test/folder-grid-ui.test.ts`.