feat: interactive /plan-devex-review + plan mode skill fix (v0.15.5.0) (#796)

* fix: skill invocation during plan mode takes precedence over generic plan mode

Adds a "Skill Invocation During Plan Mode" section to the preamble resolver so
all generated SKILL.md files include it. Fixes a bug where Claude treats loaded
skill content as reference material instead of executable instructions, and keeps
trying to ExitPlanMode instead of following the skill workflow step by step.

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

* feat: interactive /plan-devex-review with persona, benchmarks, and forcing questions

Complete rewrite of the DX review skill to match CEO/eng review depth. New flow:
investigate (persona, empathy, competitors, magical moment, journey tracing) then
force decisions, then score with evidence. Three modes: DX EXPANSION, DX POLISH,
DX TRIAGE. 20-45 interactive STOP points vs 10-12 before.

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

* chore: autoplan DX POLISH mode + review log schema for new devex fields

Adds mode selection, persona, competitive, and magical moment override rules to
autoplan Phase 3.5. Documents new review log fields (mode, persona, competitive_tier)
in the plan-file-review-report schema. Syncs package.json version to VERSION.

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

* docs: update project documentation for v0.15.5.0

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

---------

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gstack",
-  "version": "0.15.4.0",
+  "version": "0.15.5.0",
   "description": "Garry's Stack — Claude Code skills + fast headless browser. One repo, one install, entire AI engineering workflow.",
   "license": "MIT",
   "type": "module",