capy skill: name the fail heads once and describe the WARN behind outcome consistently

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

capy/skill/gstack/SKILL.md

@@ -10,7 +10,7 @@ description: Install and use gstack in Capy and Claude Code. Load at session sta
 Resolve `scripts/install.sh` relative to this SKILL.md, not the working repository. It is a frozen bootstrapper: it prints `gstack-capy-skill: wrapper <n> (<path>)` first, learns the supported minimum from gstack's remote, and hands over to the checkout's own wrapper (`bin/gstack-capy-session`).
 
 1. At session start run `bash scripts/install.sh --check`, adding `--for <skill>` when you know the workflow (`--for autoplan`, `--for review`, `--for qa`). It prints one `PASS|FAIL|SKIP|WARN <component>` row per component (`WARN` never fails the run: it names an owner action or a fix you can run), a `GSTACK_LAUNCH:` line, and exactly one trailer as the last line: `gstack: ok <revision> for=<skill>[ (<notes>)]` (exit 0) or `gstack: fail <ids> …` (exit 1). Read the exit status and grep `^gstack: ` directly; never pipe the check through `tail`, `head` or `grep` alone. `--check` never moves the checkout. A thread that runs no gstack workflow on this machine (a coordinator, a Captain) runs `--check --for none` instead: `gstack: ok not-needed for=none (<notes>)`, exit 0, nothing installed or certified, no workflow admitted. Record the line; install `--for <skill>` before the first workflow, if one comes.
-2. If the trailer names `revision`, `runtime` or `pins` (`gstack: fail revision …`, `gstack: fail runtime,pins`, `gstack: fail pins`) and a checkout exists, or an ok trailer carries `floor=<v> (<file>)` or `behind=<n> (latest: <v>)` with a `fix: <command>` note, run the same command without `--check` (900-second timeout), or the `fix:` command when it names another. `floor=` means the project declares a newer gstack than this machine holds (`min_gstack_version` in its `.gstack/ship-policy.json`; the `WARN floor` row): run the fix before the first workflow, every time. `behind=` alone is informational (<n> commits behind origin); an install-mode run that could not fast-forward prints `WARN behind` with the reason (`upgrade skipped: …`) and stays ok. Only the supported minimum (`gstack: fail revision`) fails a session for being old. Report the trailer verbatim, `behind=` and `floor=` included. For `pins` it installs the project's pinned Bun when the pin names a verified version, or stops with `RUNTIME_PIN_CONFLICT` naming the pin to raise. Any clean, unpinned checkout behind origin is fast-forwarded in install mode (below the `GSTACK_MIN_REVISION` floor by the bootstrapper, `gstack-capy-skill: upgraded <old> -> <new>`; above it by the checkout, `SELF_UPGRADE: done <old> -> <new>`), reinstalled and rechecked in one locked step. A pinned (`--revision`, detached), dirty or diverged checkout, or one another live session holds a lease on (`UPGRADE_BUSY`), is never moved: the trailer names the cause and the exact commands (above the floor it is a `fail behind` trailer after `SELF_UPGRADE: skipped (<reason>)`, with `UPGRADE_BUSY` or `UPGRADE_REFUSED`). A lease whose pid was reused after a wake is reclaimed on its own. `GSTACK_CAPY_AUTO_UPGRADE=0` disables every fast-forward, `GSTACK_CAPY_SELF_UPGRADE=off` only the above-floor one.
+2. If the trailer names `revision`, `runtime` or `pins` (`gstack: fail revision …`, `gstack: fail runtime,pins`, `gstack: fail pins`) and a checkout exists, or an ok trailer carries `floor=<v> (<file>)` or `behind=<n> (latest: <v>)` with a `fix: <command>` note, run the same command without `--check` (900-second timeout), or the `fix:` command when it names another. `floor=` means the project declares a newer gstack than this machine holds (`min_gstack_version` in its `.gstack/ship-policy.json`; the `WARN floor` row): run the fix before the first workflow, every time. `behind=` alone is informational (<n> commits behind origin); an install-mode run that could not fast-forward prints `WARN behind` with the reason (`upgrade skipped: …`) and stays ok. Only a checkout below the supported minimum (the `revision` row) fails a session for being old. Report the trailer verbatim, `behind=` and `floor=` included. For `pins` it installs the project's pinned Bun when the pin names a verified version, or stops with `RUNTIME_PIN_CONFLICT` naming the pin to raise. Any clean, unpinned checkout behind origin is fast-forwarded in install mode (below the `GSTACK_MIN_REVISION` floor by the bootstrapper, `gstack-capy-skill: upgraded <old> -> <new>`; above it by the checkout, `SELF_UPGRADE: done <old> -> <new>`), reinstalled and rechecked in one locked step. A pinned (`--revision`, detached), dirty or diverged checkout, or one another live session holds a lease on (`UPGRADE_BUSY`), is never moved: the trailer names the cause and the exact commands (above the floor it stays ok with `WARN behind` after `SELF_UPGRADE: skipped (<reason>)`, carrying `UPGRADE_BUSY` or `UPGRADE_REFUSED`). A lease whose pid was reused after a wake is reclaimed on its own. `GSTACK_CAPY_AUTO_UPGRADE=0` disables every fast-forward, `GSTACK_CAPY_SELF_UPGRADE=off` only the above-floor one.
 3. If the trailer is `gstack: fail not-installed …` and this session runs no gstack workflow, record that line and continue; nothing is installed. Install right before the first workflow with `bash scripts/install.sh --for <skill>` (about 30 s cold: clone, a SHA-256-verified Bun when none installed fits, both host profiles without Chromium, and a `~/.local/bin/bun` shim so fresh shells get the recorded Bun).
 4. Any other `FAIL` row carries a `fix:` command and a reason code with a troubleshooting anchor; run the fix, then `--check` again. `SKIP codex-cli (optional; …)`, `SKIP browser (lazy; …)`, `SKIP pins (planning-only; …)`, `SKIP pins (helper runtime; …)` and `SKIP floor (…)` are not failures. `WARN pins … (node pin only; bun pins pass)` is not one either: the Node on PATH misses the project's pin while Bun is right; run its fix only when this machine will run the project's tests.