feat: contributor mode, session awareness, recommendation format

ARCHITECTURE.md

@@ -192,7 +192,25 @@ gen-skill-docs.ts      (reads source code metadata)
 SKILL.md               (committed, auto-generated sections)
 ```
 
-Templates contain the workflows, tips, and examples that require human judgment. The `{{COMMAND_REFERENCE}}` and `{{SNAPSHOT_FLAGS}}` placeholders are filled from `commands.ts` and `snapshot.ts` at build time. This is structurally sound — if a command exists in code, it appears in docs. If it doesn't exist, it can't appear.
+Templates contain the workflows, tips, and examples that require human judgment. Placeholders are filled from source code at build time:
+
+| Placeholder | Source | What it generates |
+|-------------|--------|-------------------|
+| `{{COMMAND_REFERENCE}}` | `commands.ts` | Categorized command table |
+| `{{SNAPSHOT_FLAGS}}` | `snapshot.ts` | Flag reference with examples |
+| `{{PREAMBLE}}` | `gen-skill-docs.ts` | Startup block: update check, session tracking, contributor mode, AskUserQuestion format |
+| `{{BROWSE_SETUP}}` | `gen-skill-docs.ts` | Binary discovery + setup instructions |
+
+This is structurally sound — if a command exists in code, it appears in docs. If it doesn't exist, it can't appear.
+
+### The preamble
+
+Every skill starts with a `{{PREAMBLE}}` block that runs before the skill's own logic. It handles four things in a single bash command:
+
+1. **Update check** — calls `gstack-update-check`, reports if an upgrade is available.
+2. **Session tracking** — touches `~/.gstack/sessions/$PPID` and counts active sessions (files modified in the last 2 hours). When 3+ sessions are running, all skills enter "ELI16 mode" — every question re-grounds the user on context because they're juggling windows.
+3. **Contributor mode** — reads `gstack_contributor` from config. When true, the agent files casual field reports to `~/.gstack/contributor-logs/` when gstack itself misbehaves.
+4. **AskUserQuestion format** — universal format: context, question, `RECOMMENDATION: Choose X because ___`, lettered options. Consistent across all skills.
 
 ### Why committed, not generated at runtime?
 

CHANGELOG.md

@@ -1,5 +1,18 @@
 # Changelog
 
+## 0.4.1 — 2026-03-16
+
+- **gstack now notices when it screws up.** Turn on contributor mode (`gstack-config set gstack_contributor true`) and gstack automatically writes up what went wrong — what you were doing, what broke, repro steps. Next time something annoys you, the bug report is already written. Fork gstack and fix it yourself.
+- **Juggling multiple sessions? gstack keeps up.** When you have 3+ gstack windows open, every question now tells you which project, which branch, and what you were working on. No more staring at a question thinking "wait, which window is this?"
+- **Every question now comes with a recommendation.** Instead of dumping options on you and making you think, gstack tells you what it would pick and why. Same clear format across every skill.
+- **/review now catches forgotten enum handlers.** Add a new status, tier, or type constant? /review traces it through every switch statement, allowlist, and filter in your codebase — not just the files you changed. Catches the "added the value but forgot to handle it" class of bugs before they ship.
+
+### For contributors
+
+- Renamed `{{UPDATE_CHECK}}` to `{{PREAMBLE}}` across all 11 skill templates — one startup block now handles update check, session tracking, contributor mode, and question formatting.
+- DRY'd plan-ceo-review and plan-eng-review question formatting to reference the preamble baseline instead of duplicating rules.
+- Added CHANGELOG style guide and vendored symlink awareness docs to CLAUDE.md.
+
 ## 0.4.0 — 2026-03-16
 
 ### Added

CLAUDE.md

@@ -72,6 +72,35 @@ When you need to interact with a browser (QA, dogfooding, cookie setup), use the
 `mcp__claude-in-chrome__*` tools — they are slow, unreliable, and not what this
 project uses.
 
+## Vendored symlink awareness
+
+When developing gstack, `.claude/skills/gstack` may be a symlink back to this
+working directory (gitignored). This means skill changes are **live immediately** —
+great for rapid iteration, risky during big refactors where half-written skills
+could break other Claude Code sessions using gstack concurrently.
+
+**Check once per session:** Run `ls -la .claude/skills/gstack` to see if it's a
+symlink or a real copy. If it's a symlink to your working directory, be aware that:
+- Template changes + `bun run gen:skill-docs` immediately affect all gstack invocations
+- Breaking changes to SKILL.md.tmpl files can break concurrent gstack sessions
+- During large refactors, remove the symlink (`rm .claude/skills/gstack`) so the
+  global install at `~/.claude/skills/gstack/` is used instead
+
+**For plan reviews:** When reviewing plans that modify skill templates or the
+gen-skill-docs pipeline, consider whether the changes should be tested in isolation
+before going live (especially if the user is actively using gstack in other windows).
+
+## CHANGELOG style
+
+CHANGELOG.md is **for users**, not contributors. Write it like product release notes:
+
+- Lead with what the user can now **do** that they couldn't before. Sell the feature.
+- Use plain language, not implementation details. "You can now..." not "Refactored the..."
+- Put contributor/internal changes in a separate "For contributors" section at the bottom.
+- Every entry should make someone think "oh nice, I want to try that."
+- No jargon: say "every question now tells you which project and branch you're in" not
+  "AskUserQuestion format standardized across skill templates via preamble resolver."
+
 ## Deploying to the active skill
 
 The active skill lives at `~/.claude/skills/gstack/`. After making changes:

CONTRIBUTING.md

@@ -20,9 +20,44 @@ Now edit any `SKILL.md`, invoke it in Claude Code (e.g. `/review`), and see your
 bin/dev-teardown               # deactivate — back to your global install
 ```
 
-## How dev mode works
+## Contributor mode
 
-`bin/dev-setup` creates a `.claude/skills/` directory inside the repo (gitignored) and fills it with symlinks pointing back to your working tree. Claude Code sees the local `skills/` first, so your edits win over the global install.
+Contributor mode is for people who want to fix gstack when it annoys them. Enable it
+and Claude Code will automatically log issues to `~/.gstack/contributor-logs/` as you
+work — what you were doing, what went wrong, repro steps, raw output.
+
+```bash
+~/.claude/skills/gstack/bin/gstack-config set gstack_contributor true
+```
+
+The logs are for **you**. When something bugs you enough to fix, the report is
+already written. Fork gstack, symlink your fork into the project where you hit
+the issue, fix it, and open a PR.
+
+### The contributor workflow
+
+1. **Hit friction while using gstack** — contributor mode logs it automatically
+2. **Check your logs:** `ls ~/.gstack/contributor-logs/`
+3. **Fork and clone gstack** (if you haven't already)
+4. **Symlink your fork into the project where you hit the bug:**
+   ```bash
+   # In your core project (the one where gstack annoyed you)
+   ln -sfn /path/to/your/gstack-fork .claude/skills/gstack
+   cd .claude/skills/gstack && bun install && bun run build
+   ```
+5. **Fix the issue** — your changes are live immediately in this project
+6. **Test by actually using gstack** — do the thing that annoyed you, verify it's fixed
+7. **Open a PR from your fork**
+
+This is the best way to contribute: fix gstack while doing your real work, in the
+project where you actually felt the pain.
+
+## Working on gstack inside the gstack repo
+
+When you're editing gstack skills and want to test them by actually using gstack
+in the same repo, `bin/dev-setup` wires this up. It creates `.claude/skills/`
+symlinks (gitignored) pointing back to your working tree, so Claude Code uses
+your local edits instead of the global install.
 
 ```
 gstack/                          <- your working tree
@@ -207,69 +242,42 @@ When Conductor creates a new workspace, `bin/dev-setup` runs automatically. It d
 - **`.env` propagates across worktrees.** Set it once in the main repo, all Conductor workspaces get it.
 - **`.claude/skills/` is gitignored.** The symlinks never get committed.
 
-## Testing a branch in another repo
-
-When you're developing gstack in one workspace and want to test your branch in a
-different project (e.g. testing browse changes against your real app), there are
-two cases depending on how gstack is installed in that project.
+## Testing your changes in a real project
 
-### Global install only (no `.claude/skills/gstack/` in the project)
-
-Point your global install at the branch:
+**This is the recommended way to develop gstack.** Symlink your gstack checkout
+into the project where you actually use it, so your changes are live while you
+do real work:
 
 ```bash
-cd ~/.claude/skills/gstack
-git fetch origin
-git checkout origin/<branch>        # e.g. origin/v0.3.2
-bun install                         # in case deps changed
-bun run build                       # rebuild the binary
+# In your core project
+ln -sfn /path/to/your/gstack-checkout .claude/skills/gstack
+cd .claude/skills/gstack && bun install && bun run build
 ```
 
-Now open Claude Code in the other project — it picks up skills from
-`~/.claude/skills/` automatically. To go back to main when you're done:
+Now every gstack skill invocation in this project uses your working tree. Edit a
+template, run `bun run gen:skill-docs`, and the next `/review` or `/qa` call picks
+it up immediately.
+
+**To go back to the stable global install**, just remove the symlink:
 
 ```bash
-cd ~/.claude/skills/gstack
-git checkout main && git pull
-bun run build
+rm .claude/skills/gstack
 ```
 
-### Vendored project copy (`.claude/skills/gstack/` checked into the project)
-
-Some projects vendor gstack by copying it into the repo (no `.git` inside the
-copy). Project-local skills take priority over global, so you need to update
-the vendored copy too. This is a three-step process:
+Claude Code falls back to `~/.claude/skills/gstack/` automatically.
 
-1. **Update your global install to the branch** (so you have the source):
-   ```bash
-   cd ~/.claude/skills/gstack
-   git fetch origin
-   git checkout origin/<branch>      # e.g. origin/v0.3.2
-   bun install && bun run build
-   ```
-
-2. **Replace the vendored copy** in the other project:
-   ```bash
-   cd /path/to/other-project
+### Alternative: point your global install at a branch
 
-   # Remove old skill symlinks and vendored copy
-   for s in browse plan-ceo-review plan-eng-review review ship retro qa setup-browser-cookies; do
-     rm -f .claude/skills/$s
-   done
-   rm -rf .claude/skills/gstack
+If you don't want per-project symlinks, you can switch the global install:
 
-   # Copy from global install (strips .git so it stays vendored)
-   cp -Rf ~/.claude/skills/gstack .claude/skills/gstack
-   rm -rf .claude/skills/gstack/.git
-
-   # Rebuild binary and re-create skill symlinks
-   cd .claude/skills/gstack && ./setup
-   ```
-
-3. **Test your changes** — open Claude Code in that project and use the skills.
+```bash
+cd ~/.claude/skills/gstack
+git fetch origin
+git checkout origin/<branch>
+bun install && bun run build
+```
 
-To revert to main later, repeat steps 1-2 with `git checkout main && git pull`
-instead of `git checkout origin/<branch>`.
+This affects all projects. To revert: `git checkout main && git pull && bun run build`.
 
 ## Shipping your changes
 

SKILL.md

@@ -16,15 +16,63 @@ allowed-tools:
 <!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly -->
 <!-- Regenerate: bun run gen:skill-docs -->
 
-## Update Check (run first)
+## Preamble (run first)
 
 ```bash
 _UPD=$(~/.claude/skills/gstack/bin/gstack-update-check 2>/dev/null || .claude/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
 [ -n "$_UPD" ] && echo "$_UPD" || true
+mkdir -p ~/.gstack/sessions
+touch ~/.gstack/sessions/"$PPID"
+_SESSIONS=$(find ~/.gstack/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
+find ~/.gstack/sessions -mmin +120 -type f -delete 2>/dev/null || true
+_CONTRIB=$(~/.claude/skills/gstack/bin/gstack-config get gstack_contributor 2>/dev/null || true)
 ```
 
 If output shows `UPGRADE_AVAILABLE <old> <new>`: read `~/.claude/skills/gstack/gstack-upgrade/SKILL.md` and follow the "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined). If `JUST_UPGRADED <from> <to>`: tell user "Running gstack v{to} (just updated!)" and continue.
 
+## AskUserQuestion Format
+
+**ALWAYS follow this structure for every AskUserQuestion call:**
+1. Context: project name, current branch, what we're working on (1-2 sentences)
+2. The specific question or decision point
+3. `RECOMMENDATION: Choose [X] because [one-line reason]`
+4. Lettered options: `A) ... B) ... C) ...`
+
+If `_SESSIONS` is 3 or more: the user is juggling multiple gstack sessions and context-switching heavily. **ELI16 mode** — they may not remember what this conversation is about. Every AskUserQuestion MUST re-ground them: state the project, the branch, the current plan/task, then the specific problem, THEN the recommendation and options. Be extra clear and self-contained — assume they haven't looked at this window in 20 minutes.
+
+Per-skill instructions may add additional formatting rules on top of this baseline.
+
+## Contributor Mode
+
+If `_CONTRIB` is `true`: you are in **contributor mode**. When you hit friction with **gstack itself** (not the user's app), file a field report. Think: "hey, I was trying to do X with gstack and it didn't work / was confusing / was annoying. Here's what happened."
+
+**gstack issues:** browse command fails/wrong output, snapshot missing elements, skill instructions unclear or misleading, binary crash/hang, unhelpful error message, any rough edge or annoyance — even minor stuff.
+**NOT gstack issues:** user's app bugs, network errors to user's URL, auth failures on user's site.
+
+**To file:** write `~/.gstack/contributor-logs/{slug}.md` with this structure:
+
+```
+# {Title}
+
+Hey gstack team — ran into this while using /{skill-name}:
+
+**What I was trying to do:** {what the user/agent was attempting}
+**What happened instead:** {what actually happened}
+**How annoying (1-5):** {1=meh, 3=friction, 5=blocker}
+
+## Steps to reproduce
+1. {step}
+
+## Raw output
+(wrap any error messages or unexpected output in a markdown code block)
+
+**Date:** {YYYY-MM-DD} | **Version:** {gstack version} | **Skill:** /{skill}
+```
+
+Then run: `mkdir -p ~/.gstack/contributor-logs && open ~/.gstack/contributor-logs/{slug}.md`
+
+Slug: lowercase, hyphens, max 60 chars (e.g. `browse-snapshot-ref-gap`). Skip if file already exists. Max 3 reports per session. File inline and continue — don't stop the workflow. Tell user: "Filed gstack field report: {title}"
+
 # gstack browse: QA Testing & Dogfooding
 
 Persistent headless Chromium. First call auto-starts (~3s), then ~100-200ms per command.

SKILL.md.tmpl

@@ -14,7 +14,7 @@ allowed-tools:
 
 ---
 
-{{UPDATE_CHECK}}
+{{PREAMBLE}}
 
 # gstack browse: QA Testing & Dogfooding
 

VERSION

@@ -1 +1 @@
-0.4.0
+0.4.1

browse/SKILL.md

@@ -16,15 +16,63 @@ allowed-tools:
 <!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly -->
 <!-- Regenerate: bun run gen:skill-docs -->
 
-## Update Check (run first)
+## Preamble (run first)
 
 ```bash
 _UPD=$(~/.claude/skills/gstack/bin/gstack-update-check 2>/dev/null || .claude/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
 [ -n "$_UPD" ] && echo "$_UPD" || true
+mkdir -p ~/.gstack/sessions
+touch ~/.gstack/sessions/"$PPID"
+_SESSIONS=$(find ~/.gstack/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
+find ~/.gstack/sessions -mmin +120 -type f -delete 2>/dev/null || true
+_CONTRIB=$(~/.claude/skills/gstack/bin/gstack-config get gstack_contributor 2>/dev/null || true)
 ```
 
 If output shows `UPGRADE_AVAILABLE <old> <new>`: read `~/.claude/skills/gstack/gstack-upgrade/SKILL.md` and follow the "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined). If `JUST_UPGRADED <from> <to>`: tell user "Running gstack v{to} (just updated!)" and continue.
 
+## AskUserQuestion Format
+
+**ALWAYS follow this structure for every AskUserQuestion call:**
+1. Context: project name, current branch, what we're working on (1-2 sentences)
+2. The specific question or decision point
+3. `RECOMMENDATION: Choose [X] because [one-line reason]`
+4. Lettered options: `A) ... B) ... C) ...`
+
+If `_SESSIONS` is 3 or more: the user is juggling multiple gstack sessions and context-switching heavily. **ELI16 mode** — they may not remember what this conversation is about. Every AskUserQuestion MUST re-ground them: state the project, the branch, the current plan/task, then the specific problem, THEN the recommendation and options. Be extra clear and self-contained — assume they haven't looked at this window in 20 minutes.
+
+Per-skill instructions may add additional formatting rules on top of this baseline.
+
+## Contributor Mode
+
+If `_CONTRIB` is `true`: you are in **contributor mode**. When you hit friction with **gstack itself** (not the user's app), file a field report. Think: "hey, I was trying to do X with gstack and it didn't work / was confusing / was annoying. Here's what happened."
+
+**gstack issues:** browse command fails/wrong output, snapshot missing elements, skill instructions unclear or misleading, binary crash/hang, unhelpful error message, any rough edge or annoyance — even minor stuff.
+**NOT gstack issues:** user's app bugs, network errors to user's URL, auth failures on user's site.
+
+**To file:** write `~/.gstack/contributor-logs/{slug}.md` with this structure:
+
+```
+# {Title}
+
+Hey gstack team — ran into this while using /{skill-name}:
+
+**What I was trying to do:** {what the user/agent was attempting}
+**What happened instead:** {what actually happened}
+**How annoying (1-5):** {1=meh, 3=friction, 5=blocker}
+
+## Steps to reproduce
+1. {step}
+
+## Raw output
+(wrap any error messages or unexpected output in a markdown code block)
+
+**Date:** {YYYY-MM-DD} | **Version:** {gstack version} | **Skill:** /{skill}
+```
+
+Then run: `mkdir -p ~/.gstack/contributor-logs && open ~/.gstack/contributor-logs/{slug}.md`
+
+Slug: lowercase, hyphens, max 60 chars (e.g. `browse-snapshot-ref-gap`). Skip if file already exists. Max 3 reports per session. File inline and continue — don't stop the workflow. Tell user: "Filed gstack field report: {title}"
+
 # browse: QA Testing & Dogfooding
 
 Persistent headless Chromium. First call auto-starts (~3s), then ~100ms per command.

browse/SKILL.md.tmpl

@@ -14,7 +14,7 @@ allowed-tools:
 
 ---
 
-{{UPDATE_CHECK}}
+{{PREAMBLE}}
 
 # browse: QA Testing & Dogfooding