fix(setup-gbrain): invoke gstack-memory-ingest/gstack-gbrain-sync via bun run + .ts

/setup-gbrain's transcript-ingest steps told the agent to run
bin/gstack-memory-ingest and bin/gstack-gbrain-sync by BARE name. Neither
exists — only the .ts files ship (mode 644, no bin alias) — so the agent
dutifully reported 'script missing at install root' and the ingest/full-
sync steps dead-ended on every host (hit live under Codex; the Claude
render carries the same text).

All four template sites (probe, silent-bulk, post-answer full sync, the
preamble-hook incremental mention) and the four memory.md reference-doc
sites now use the repo's established form: 'bun run <path>/gstack-memory-
ingest.ts …' / 'bun run <path>/gstack-gbrain-sync.ts …' — matching what
sync-gbrain already does. Generated SKILL.md regenerated from the template
in the same commit.

Re-derived from PR #2409 by @SomSamantray per the wave's screening rule
(the PR edited the generated SKILL.md directly; the generated file must
come from gen:skill-docs). The contributor's structural test rides along
as-is: bare-invocation regexes with negative .ts lookahead and backslash-
continuation coverage pin every site, so the drift can't return. The
referenced-paths ratchet in test/setup-claude-skill-assets.test.ts drops
its two #2250 known-broken entries — the class-2 assertion now guards
these paths again.

Verified against #2250's site list (template lines 690/735/784-area, all
covered) plus a fresh grep: zero bare invocations remain in the template
or memory.md; the one prose mention ('gstack-memory-ingest now persists…')
is not an invocation and stays.

Fixes #2250
Fixes #2393

Co-authored-by: SomSamantray <SomSamantray@users.noreply.github.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

setup-gbrain/SKILL.md

@@ -1503,7 +1503,7 @@ curated `~/.gstack/` artifacts into gbrain so the retrieval surface
 
 Run the probe to size the operation:
 ```bash
-~/.claude/skills/gstack/bin/gstack-memory-ingest --probe
+bun run ~/.claude/skills/gstack/bin/gstack-memory-ingest.ts --probe
 ```
 
 Read the output. If `Total files in window: 0`, skip — there's nothing
@@ -1511,7 +1511,7 @@ to ingest. Set `gstack-config set transcript_ingest_mode incremental`
 silently and continue to Step 8.
 
 If `New (never ingested)` is < 200 AND total bytes are < 100MB: silent
-bulk via `gstack-memory-ingest --bulk --quiet`. Set
+bulk via `bun run ~/.claude/skills/gstack/bin/gstack-memory-ingest.ts --bulk --quiet`. Set
 `transcript_ingest_mode=incremental` and continue.
 
 Otherwise (the "many transcripts on disk" path): AskUserQuestion with
@@ -1548,14 +1548,14 @@ Options:
 After answer:
 ```bash
 ~/.claude/skills/gstack/bin/gstack-config set transcript_ingest_mode <choice>
-~/.claude/skills/gstack/bin/gstack-gbrain-sync --full --no-brain-sync
+bun run ~/.claude/skills/gstack/bin/gstack-gbrain-sync.ts --full --no-brain-sync
 ```
 (`--no-brain-sync` because Step 7 already wired that path; this just
 runs the code import + memory ingest stages. Brain-sync will run on the
 next preamble hook.)
 
 If A/D/E, ingest is incremental from this point on; preamble-boundary
-hook runs `gstack-gbrain-sync --incremental --quiet` on every skill
+hook runs `bun run ~/.claude/skills/gstack/bin/gstack-gbrain-sync.ts --incremental --quiet` on every skill
 start (cheap mtime fast-path).
 
 Reference doc for users: `setup-gbrain/memory.md` (linked from CLAUDE.md