Add testing skill for Muninn app

.agents/skills/testing-muninn/SKILL.md

@@ -0,0 +1,95 @@
+# Testing Muninn
+
+## Prerequisites
+
+### Devin Secrets Needed
+- `VITE_SUPABASE_URL` — Supabase project URL (e.g. `https://xxx.supabase.co`)
+- `VITE_SUPABASE_ANON_KEY` — Supabase anonymous/public API key
+
+These must be written to a `.env` file in the repo root before starting the dev server.
+
+## Setup
+
+```bash
+# Write .env (values from secrets)
+echo "VITE_SUPABASE_URL=$VITE_SUPABASE_URL" > .env
+echo "VITE_SUPABASE_ANON_KEY=$VITE_SUPABASE_ANON_KEY" >> .env
+
+# Start dev server
+npm run dev
+# App runs at http://localhost:5173
+```
+
+The app will throw a descriptive error on startup if the env vars are missing.
+If the Supabase key is invalid/expired, the app will load but all API calls will fail with "Invalid API key" — the ErrorToast component will surface this.
+
+## Chrome Setup
+
+Chrome must be launched with CDP on port 29229 for the `google-chrome` wrapper to work:
+
+```bash
+/opt/.devin/chrome/chrome/linux-137.0.7118.2/chrome-linux64/chrome \
+  --remote-debugging-port=29229 \
+  --no-first-run \
+  --disable-session-crashed-bubble \
+  --no-default-browser-check \
+  --user-data-dir=/tmp/chrome-profile \
+  http://localhost:5173/ &disown
+```
+
+The Chrome binary path might change — check `/opt/.devin/chrome/` for available versions if the above path doesn't exist.
+
+## UI Navigation
+
+### Sidebar (left)
+The sidebar has 4 icon buttons (top to bottom):
+1. **Board** (kanban icon) → `/` — Kanban board with 5 columns (Idea, Todo, In-Progress, Paused, Done)
+2. **Tools** (grid icon) → `/tools` — AI tools dashboard with cost tracking
+3. **Agents** (lightning icon) → `/agents` — Agent session feed
+4. **Settings** (gear icon) → `/settings` — Theme toggle + Supabase connection status
+
+### Key UI Flows
+
+**Create Project:**
+- Click "+ New Project" button (top-right on Board page)
+- Panel opens on right with form: Name, Status (dropdown), Priority (0-5), Description, Tech Stack (comma-separated)
+- "Create Project" button is disabled when name is empty
+
+**View/Edit Project:**
+- Click any project card on the Kanban board
+- Detail panel opens with project data
+- Fields auto-save on change (priority is debounced 600ms)
+
+**Delete Project/Tool:**
+- Open detail panel for a project or tool
+- Scroll to bottom → click red "Delete" button → confirm in dialog
+
+**Theme Toggle:**
+- Go to Settings → click moon/sun icon button
+- Theme persists across page refresh via localStorage (`muninn-ui` key)
+
+**Panel Close:**
+- Click X button in panel header, or press Escape
+- Both methods clear selection state (no stale data on re-open)
+
+## What to Test
+
+### Requires valid Supabase credentials
+- Project CRUD (create, read in detail panel, update fields, delete)
+- Tool CRUD
+- Drag-and-drop between Kanban columns
+- Settings connection check (should show green dot + "Supabase Connected")
+
+### Testable without Supabase
+- Create form UI rendering and field validation
+- Panel open/close mechanics (X button + Escape)
+- Theme toggle + localStorage persistence
+- Navigation between all 4 pages
+- ErrorToast component (will show API errors)
+- Settings page layout and connection check error state
+
+## Known Gotchas
+- The `google-chrome` wrapper script at `~/.local/bin/google-chrome` uses CDP on port 29229. If Chrome isn't already running with CDP, the wrapper will fail with "Connection refused". You need to manually launch Chrome with `--remote-debugging-port=29229`.
+- The Supabase anon key might be expired or rotated — if you see "Invalid API key" errors, ask the user for a fresh key.
+- There is no automated test suite in this project — all testing is manual UI testing.
+- The app uses Zustand devtools — you can inspect state in browser devtools if needed.