add-featurelisted

# Add a feature Follow these steps in order. Look at an existing feature first — `src/app/(app)/generate/` is the reference implementation of this shape. ## 1. Spec it Copy `specs/TEMPLATE.md` to `specs/NNN-short-name.md` and fill it in (problem, solution, out-of-scope, data changes, test plan). Two paragraphs beat zero. Show the user before writing code. ## 2. Data (only if the spec says so) If the feature needs schema changes, stop and run `/db-migration`. Schema changes require asking the user first. ## 3. Server action Create `src/app/(app)/<feature>/actions.ts`: - `"use server"` at the top. - First line of every action: re-check the session via the helper in `src/lib/auth/` — never rely on middleware alone. Throw/redirect if absent. - Validate all input with a Zod schema. Parse, don't cast. - Mutations that touch credits go through `src/lib/credits/` only. - Return typed results; `revalidatePath` what the mutation changed. ## 4. Page Create `src/app/(app)/<feature>/page.tsx`: - Server Component. Fetch data directly (Drizzle), no client fetching. - Re-check the session server-side, same as the action. - `"use client"` only for leaf components that need interactivity (forms, toggles) — keep them small, pass data down from the RSC. - UI per DESIGN.md: existing shadcn primitives from `src/components/ui/`, ledger rows for lists, mono for numbers/labels, no new colors. ## 5. Navigation Add the page to the sidebar nav in the app shell component (one entry: lu