feat: community wave — 7 fixes, relink, sidebar Write, discoverability (v0.13.5.0) (#641)

* test: add 16 failing tests for 6 community fixes

Tests-first for all fixes in this PR wave:
- #594 discoverability: gstack tag in descriptions, 120-char first line
- #573 feature signals: ship/SKILL.md Step 4 detection
- #510 context warnings: no preemptive warnings in generated files
- #474 Safety Net: no find -delete in generated files
- #467 telemetry: JSONL writes gated by _TEL conditional
- #584 sidebar: Write in allowedTools, stderr capture
- #578 relink: prefixed/flat symlinks, cleanup, error, config hook

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: replace find -delete with find -exec rm for Safety Net (#474)

-delete is a non-POSIX extension that fails on Safety Net environments.
-exec rm {} + is POSIX-compliant and works everywhere.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: gate local JSONL writes by telemetry setting (#467)

When telemetry is off, nothing is written anywhere — not just remote,
but local JSONL too. Clean trust contract: off means off everywhere.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: remove preemptive context warnings from plan-eng-review (#510)

The system handles context compaction automatically. Preemptive warnings
waste tokens and create false urgency. Skills should not warn about
context limits — just describe the compression priority order.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add (gstack) tag to skill descriptions for discoverability (#594)

Every SKILL.md.tmpl description now contains "gstack" on the last line,
making skills findable in Claude Code's command palette. First-line hooks
stay under 120 chars. Split ship description to fix wrapping.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: auto-relink skill symlinks on prefix config change (#578)

New bin/gstack-relink creates prefixed (gstack-*) or flat symlinks
based on skill_prefix config. gstack-config auto-triggers relink
when skill_prefix changes. Setup guards against recursive calls
with GSTACK_SETUP_RUNNING env var.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: add feature signal detection to version bump heuristic (#573)

/ship Step 4 now checks for feature signals (new routes, migrations,
test+source pairs, feat/ branches) when deciding version bumps.
PATCH requires no feature signals. MINOR asks the user if any signal
is detected or 500+ lines changed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: sidebar Write tool, stderr capture, cross-platform URL opener (#584)

Add Write to sidebar allowedTools (both sidebar-agent.ts and server.ts).
Write doesn't expand attack surface beyond what Bash already provides.
Replace empty stderr handler with buffer capture for better error
diagnostics. New bin/gstack-open-url for cross-platform URL opening.

Does NOT include Search Before Building intro flow (deferred).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: update sidebar-security test for Write tool addition

The fallback allowedTools string now includes Write, matching the
sidebar-agent.ts change from commit 68dc957.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: bump version and changelog (v0.13.5.0)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: prevent gstack-relink from double-prefixing gstack-upgrade

gstack-relink now checks if a skill directory is already named gstack-*
before prepending the prefix. Previously, setting skill_prefix=true would
create gstack-gstack-upgrade, breaking the /gstack-upgrade command.

Matches setup script behavior (setup:260) which already has this guard.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: add double-prefix fix to changelog

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: remove .factory/ from git tracking and add to .gitignore

Generated Factory Droid skills are build output, same as .agents/.
They should not be committed to the repo.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

guard/SKILL.md

@@ -6,7 +6,7 @@ description: |
   Combines /careful (warns before rm -rf, DROP TABLE, force-push, etc.) with
   /freeze (blocks edits outside a specified directory). Use for maximum safety
   when touching prod or debugging live systems. Use when asked to "guard mode",
-  "full safety", "lock it down", or "maximum safety".
+  "full safety", "lock it down", or "maximum safety". (gstack)
 allowed-tools:
   - Bash
   - Read

guard/SKILL.md.tmpl

@@ -6,7 +6,7 @@ description: |
   Combines /careful (warns before rm -rf, DROP TABLE, force-push, etc.) with
   /freeze (blocks edits outside a specified directory). Use for maximum safety
   when touching prod or debugging live systems. Use when asked to "guard mode",
-  "full safety", "lock it down", or "maximum safety".
+  "full safety", "lock it down", or "maximum safety". (gstack)
 allowed-tools:
   - Bash
   - Read