fix(edit-history): colons in file:// paths, yield on forward reads, no store for unsupported

Follow-up from an own review pass of de436576:
- PATH_TOKEN_RE branch 1 stops at the next `file://` instead of at `:`,
  so `file:///tmp/plot-12:30.png` is found again; still linear.
- Forward reads yield between files like "Load older"; a store removed
  meanwhile ends the read and its printed paths are never probed.
- POST /edits/older and GET /edits/:entryId no longer load a store for
  remote, Docker or non-claude sessions (shared unsupportedList()).
- Time budgets widened (1 s per line, 3 s per chunk; ~3 s / 6.6 s before
  the fix) so the throttled suite does not flake.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture-invariants.md

@@ -736,7 +736,7 @@ Matching semantics: a query containing `/` matches the relative path, otherwise
 
 ⚠️ **Images only through existing file surfaces.** A Bash image candidate counts only when the file's mtime lies in the call's window (start − 2 s … end + 2 s) and no entry already covers that file version; `SendUserFile` images need no window. The panel shows a thumbnail only inside the workspace, through the confined `file-raw` route. An image outside it gets no thumbnail (each would mint an attachment id per render); a click opens the shared file preview, which registers it once through `POST /api/sessions/:id/attachments` with `notify: false` (its extension allowlist and `isSensitivePath` apply). SVGs get no thumbnail. No route of this feature serves a file, least of all a transcript path.
 
-⚠️ **Transcript paths are agent-printed, so they are probed BOUNDED and scanned in linear time** (#516; #693 review). `probeLocalPaths()` sends each candidate through `probePathKind()` (no `pastCap`: a bulk scan), one at a time, and only a path that answered `'file'` gets `realpath` + `stat`; a path on a mount that stopped answering costs one stalled stat, never a sync, a queued sync or `remove()` that cannot finish (`test/edit-history-probe-stall.test.ts`). `PATH_TOKEN_RE` runs synchronously in the request, over Bash output of up to 30,000 characters: an unquoted token may start only at a token boundary (line start or a token-ending character, `:` excluded so URLs stay ignored), and the `file://` branch stops at `:`. A lookbehind that merely excludes some characters lets a match start at every character of a long token and rescan it, quadratic in the line (2.7 s for 30,000 `#`). Time-budget regression tests in `test/edit-history-parse.test.ts`. "Load older" yields to the event loop between the files it parses (up to 3 × 8 MiB).
+⚠️ **Transcript paths are agent-printed, so they are probed BOUNDED and scanned in linear time** (#516; #693 review). `probeLocalPaths()` sends each candidate through `probePathKind()` (no `pastCap`: a bulk scan), one at a time, and only a path that answered `'file'` gets `realpath` + `stat`; a path on a mount that stopped answering costs one stalled stat, never a sync, a queued sync or `remove()` that cannot finish (`test/edit-history-probe-stall.test.ts`). `PATH_TOKEN_RE` runs synchronously in the request, over Bash output of up to 30,000 characters: an unquoted token may start only at a token boundary (line start or a token-ending character, `:` excluded so URLs stay ignored), and the `file://` branch stops at the next `file://` (`:` stays allowed for timestamped names). A lookbehind that merely excludes some characters lets a match start at every character of a long token and rescan it, quadratic in the line (2.7 s for 30,000 `#`). Time-budget regression tests in `test/edit-history-parse.test.ts`. Forward reads and "Load older" yield to the event loop between the files they parse (up to 8 MiB each); a store removed meanwhile ends the read before its images are probed. Remote, Docker and non-claude sessions never load a store on any route.
 
 Paths, agent descriptions and diff lines render via `textContent` only (browser test with a hostile path). The header button uses the marker-class pattern (`btn-edit-history--hidden`) and stays off phones (`mobile.css`, locked in `test/mobile-header-buttons-policy.test.ts`). Remote, Docker and non-claude sessions answer `unsupported` and are never read.