feat: add Gemini CLI as cross-model second-opinion provider

.agents/skills/gstack-autoplan/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-autoplan"
-  short_description: "Auto-review pipeline — reads the full CEO, design, and eng review skills from disk and runs them sequentially with..."
+  short_description: ""
   default_prompt: "Use gstack-autoplan for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-benchmark/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-benchmark"
-  short_description: "Performance regression detection using the browse daemon. Establishes baselines for page load times, Core Web..."
+  short_description: ""
   default_prompt: "Use gstack-benchmark for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-browse/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-browse"
-  short_description: "Fast headless browser for QA testing and site dogfooding. Navigate any URL, interact with elements, verify page..."
+  short_description: ""
   default_prompt: "Use gstack-browse for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-canary/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-canary"
-  short_description: "Post-deploy canary monitoring. Watches the live app for console errors, performance regressions, and page failures..."
+  short_description: ""
   default_prompt: "Use gstack-canary for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-careful/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-careful"
-  short_description: "Safety guardrails for destructive commands. Warns before rm -rf, DROP TABLE, force-push, git reset --hard, kubectl..."
+  short_description: ""
   default_prompt: "Use gstack-careful for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-connect-chrome/SKILL.md

@@ -1,11 +1,17 @@
 ---
 name: connect-chrome
+version: 0.1.0
 description: |
   Launch real Chrome controlled by gstack with the Side Panel extension auto-loaded.
   One command: connects Claude to a visible Chrome window where you can watch every
   action in real time. The extension shows a live activity feed in the Side Panel.
   Use when asked to "connect chrome", "open chrome", "real browser", "launch chrome",
   "side panel", or "control my browser".
+allowed-tools:
+  - Bash
+  - Read
+  - AskUserQuestion
+
 ---
 <!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly -->
 <!-- Regenerate: bun run gen:skill-docs -->

.agents/skills/gstack-cso/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-cso"
-  short_description: "Chief Security Officer mode. Infrastructure-first security audit: secrets archaeology, dependency supply chain,..."
+  short_description: ""
   default_prompt: "Use gstack-cso for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-design-consultation/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-design-consultation"
-  short_description: "Design consultation: understands your product, researches the landscape, proposes a complete design system..."
+  short_description: ""
   default_prompt: "Use gstack-design-consultation for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-design-review/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-design-review"
-  short_description: "Designer's eye QA: finds visual inconsistency, spacing issues, hierarchy problems, AI slop patterns, and slow..."
+  short_description: ""
   default_prompt: "Use gstack-design-review for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-document-release/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-document-release"
-  short_description: "Post-ship documentation update. Reads all project docs, cross-references the diff, updates..."
+  short_description: ""
   default_prompt: "Use gstack-document-release for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-freeze/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-freeze"
-  short_description: "Restrict file edits to a specific directory for the session. Blocks Edit and Write outside the allowed path. Use..."
+  short_description: ""
   default_prompt: "Use gstack-freeze for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-guard/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-guard"
-  short_description: "Full safety mode: destructive command warnings + directory-scoped edits. Combines /careful (warns before rm -rf,..."
+  short_description: ""
   default_prompt: "Use gstack-guard for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-investigate/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-investigate"
-  short_description: "Systematic debugging with root cause investigation. Four phases: investigate, analyze, hypothesize, implement. Iron..."
+  short_description: ""
   default_prompt: "Use gstack-investigate for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-land-and-deploy/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-land-and-deploy"
-  short_description: "Land and deploy workflow. Merges the PR, waits for CI and deploy, verifies production health via canary checks...."
+  short_description: ""
   default_prompt: "Use gstack-land-and-deploy for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-office-hours/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-office-hours"
-  short_description: "YC Office Hours — two modes. Startup mode: six forcing questions that expose demand reality, status quo, desperate..."
+  short_description: ""
   default_prompt: "Use gstack-office-hours for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-plan-ceo-review/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-plan-ceo-review"
-  short_description: "CEO/founder-mode plan review. Rethink the problem, find the 10-star product, challenge premises, expand scope when..."
+  short_description: ""
   default_prompt: "Use gstack-plan-ceo-review for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-plan-design-review/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-plan-design-review"
-  short_description: "Designer's eye plan review — interactive, like CEO and Eng review. Rates each design dimension 0-10, explains what..."
+  short_description: ""
   default_prompt: "Use gstack-plan-design-review for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-plan-eng-review/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-plan-eng-review"
-  short_description: "Eng manager-mode plan review. Lock in the execution plan — architecture, data flow, diagrams, edge cases, test..."
+  short_description: ""
   default_prompt: "Use gstack-plan-eng-review for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-qa-only/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-qa-only"
-  short_description: "Report-only QA testing. Systematically tests a web application and produces a structured report with health score,..."
+  short_description: ""
   default_prompt: "Use gstack-qa-only for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-qa/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-qa"
-  short_description: "Systematically QA test a web application and fix bugs found. Runs QA testing, then iteratively fixes bugs in source..."
+  short_description: ""
   default_prompt: "Use gstack-qa for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-retro/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-retro"
-  short_description: "Weekly engineering retrospective. Analyzes commit history, work patterns, and code quality metrics with persistent..."
+  short_description: ""
   default_prompt: "Use gstack-retro for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-review/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-review"
-  short_description: "Pre-landing PR review. Analyzes diff against the base branch for SQL safety, LLM trust boundary violations,..."
+  short_description: ""
   default_prompt: "Use gstack-review for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-setup-browser-cookies/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-setup-browser-cookies"
-  short_description: "Import cookies from your real Chromium browser into the headless browse session. Opens an interactive picker UI..."
+  short_description: ""
   default_prompt: "Use gstack-setup-browser-cookies for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-setup-deploy/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-setup-deploy"
-  short_description: "Configure deployment settings for /land-and-deploy. Detects your deploy platform (Fly.io, Render, Vercel, Netlify,..."
+  short_description: ""
   default_prompt: "Use gstack-setup-deploy for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-ship/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-ship"
-  short_description: "Ship workflow: detect + merge base branch, run tests, review diff, bump VERSION, update CHANGELOG, commit, push,..."
+  short_description: ""
   default_prompt: "Use gstack-ship for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-unfreeze/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-unfreeze"
-  short_description: "Clear the freeze boundary set by /freeze, allowing edits to all directories again. Use when you want to widen edit..."
+  short_description: ""
   default_prompt: "Use gstack-unfreeze for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack-upgrade/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack-upgrade"
-  short_description: "Upgrade gstack to the latest version. Detects global vs vendored install, runs the upgrade, and shows what's new...."
+  short_description: ""
   default_prompt: "Use gstack-upgrade for this task."
 policy:
   allow_implicit_invocation: true

.agents/skills/gstack/agents/openai.yaml

@@ -1,6 +1,6 @@
 interface:
   display_name: "gstack"
-  short_description: "Fast headless browser for QA testing and site dogfooding. Navigate pages, interact with elements, verify state, diff..."
+  short_description: ""
   default_prompt: "Use gstack for this task."
 policy:
   allow_implicit_invocation: true

SKILL.md

@@ -44,7 +44,7 @@ _SESSION_ID="$$-$(date +%s)"
 echo "TELEMETRY: ${_TEL:-off}"
 echo "TEL_PROMPTED: $_TEL_PROMPTED"
 mkdir -p ~/.gstack/analytics
-echo '{"skill":"gstack","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> ~/.gstack/analytics/skill-usage.jsonl 2>/dev/null || true
+echo '{"skill":"gstack-contrib","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> ~/.gstack/analytics/skill-usage.jsonl 2>/dev/null || true
 # zsh-compatible: use find instead of glob to avoid NOMATCH error
 for _PF in $(find ~/.gstack/analytics -maxdepth 1 -name '.pending-*' 2>/dev/null); do [ -f "$_PF" ] && ~/.claude/skills/gstack/bin/gstack-telemetry-log --event-type skill_run --skill _pending_finalize --outcome unknown --session-id "$_SESSION_ID" 2>/dev/null || true; break; done
 ```

design-consultation/SKILL.md

@@ -463,14 +463,25 @@ Use AskUserQuestion:
 
 If user chooses B, skip this step and continue.
 
-**Check Codex availability:**
+**Detect available second-opinion provider:**
 ```bash
-which codex 2>/dev/null && echo "CODEX_AVAILABLE" || echo "CODEX_NOT_AVAILABLE"
+SECOND_OPINION_BIN=""
+SECOND_OPINION_PROVIDER=""
+if which codex 2>/dev/null; then
+  SECOND_OPINION_BIN="codex"
+  SECOND_OPINION_PROVIDER="Codex"
+elif which gemini 2>/dev/null; then
+  SECOND_OPINION_BIN="gemini"
+  SECOND_OPINION_PROVIDER="Gemini"
+fi
+echo "${SECOND_OPINION_PROVIDER:-NONE}_AVAILABLE"
 ```
 
-**If Codex is available**, launch both voices simultaneously:
+**If a provider is available**, launch both voices simultaneously:
+
+1. **Cross-model design voice** (via Bash):
 
-1. **Codex design voice** (via Bash):
+**If Codex:**
 ```bash
 TMPERR_DESIGN=$(mktemp /tmp/codex-design-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
@@ -484,6 +495,21 @@ codex exec "Given this product context, propose a complete design direction:
 
 Be opinionated. Be specific. Do not hedge. This is YOUR design direction — own it." -C "$_REPO_ROOT" -s read-only -c 'model_reasoning_effort="medium"' --enable web_search_cached 2>"$TMPERR_DESIGN"
 ```
+
+**If Gemini:**
+```bash
+TMPERR_DESIGN=$(mktemp /tmp/gemini-design-XXXXXXXX)
+gemini --prompt "Given this product context, propose a complete design direction:
+- Visual thesis: one sentence describing mood, material, and energy
+- Typography: specific font names (not defaults — no Inter/Roboto/Arial/system) + hex colors
+- Color system: CSS variables for background, surface, primary text, muted text, accent
+- Layout: composition-first, not component-first. First viewport as poster, not document
+- Differentiation: 2 deliberate departures from category norms
+- Anti-slop: no purple gradients, no 3-column icon grids, no centered everything, no decorative blobs
+
+Be opinionated. Be specific. Do not hedge. This is YOUR design direction — own it." 2>"$TMPERR_DESIGN"
+```
+
 Use a 5-minute timeout (`timeout: 300000`). After the command completes, read stderr:
 ```bash
 cat "$TMPERR_DESIGN" && rm -f "$TMPERR_DESIGN"
@@ -499,13 +525,13 @@ Dispatch a subagent with this prompt:
 Be bold. Be specific. No hedging."
 
 **Error handling (all non-blocking):**
-- **Auth failure:** If stderr contains "auth", "login", "unauthorized", or "API key": "Codex authentication failed. Run `codex login` to authenticate."
-- **Timeout:** "Codex timed out after 5 minutes."
-- **Empty response:** "Codex returned no response."
-- On any Codex error: proceed with Claude subagent output only, tagged `[single-model]`.
+- **Auth failure:** If stderr contains "auth", "login", "unauthorized", or "API key": "[Provider] authentication failed. Run \`codex login\` or \`gemini\` to authenticate."
+- **Timeout:** "[Provider] timed out after 5 minutes."
+- **Empty response:** "[Provider] returned no response."
+- On any provider error: proceed with Claude subagent output only, tagged `[single-model]`.
 - If Claude subagent also fails: "Outside voices unavailable — continuing with primary review."
 
-Present Codex output under a `CODEX SAYS (design direction):` header.
+Present cross-model output under a `{PROVIDER} SAYS (design direction):` header (substituting Codex or Gemini).
 Present subagent output under a `CLAUDE SUBAGENT (design direction):` header.
 
 **Synthesis:** Claude main references both Codex and subagent proposals in the Phase 3 proposal. Present:
@@ -517,7 +543,7 @@ Present subagent output under a `CLAUDE SUBAGENT (design direction):` header.
 ```bash
 ~/.claude/skills/gstack/bin/gstack-review-log '{"skill":"design-outside-voices","timestamp":"'"$(date -u +%Y-%m-%dT%H:%M:%SZ)"'","status":"STATUS","source":"SOURCE","commit":"'"$(git rev-parse --short HEAD)"'"}'
 ```
-Replace STATUS with "clean" or "issues_found", SOURCE with "codex+subagent", "codex-only", "subagent-only", or "unavailable".
+Replace STATUS with "clean" or "issues_found", SOURCE with "codex+subagent", "gemini+subagent", "codex-only", "gemini-only", "subagent-only", or "unavailable".
 
 ## Phase 3: The Complete Proposal