feat: add prompt library view

[arnestrickmann]

Summary

This adds a Library entry to the left sidebar and uses it as the shared home for reusable agent assets. The Library opens on a new Prompts tab, with Skills and MCP moved into sibling tabs that reuse their existing views and behavior.

The Prompts tab lets users manage prompt presets that can be inserted from task prompt menus. It includes the built-in review prompt, supports editing/resetting that review prompt, and adds custom prompt presets with create, edit, delete, and search flows. Custom prompts are persisted in app settings so they are available across tasks without introducing a new storage path.

The task bottom bar and create-task modal now expose prompts through a compact Prompts popover. Long prompt bodies are truncated by default, can be expanded inline for review, and the menu scrolls when many presets are available. The trigger intentionally stays compact and does not show a prompt count badge, which keeps the bottom bar stable as users add more presets.

promptlibraryfeature.mp4

Implementation Notes

• Registers a new library view and prompt modal using the existing renderer registries.
• Adds promptLibrary to app settings schema/defaults and updates the settings hook so array settings replace cleanly instead of being object-merged.
• Extends context actions with custom prompt entries, then shares the prompt popover between the task context bar and create-task modal.
• Keeps the existing Skills and MCP implementations intact by rendering them inside the Library tab shell.

Validation

• pnpm run format
• pnpm run lint passes with the existing command-palette-modal.tsx warning
• pnpm run typecheck
• pnpm rebuild better-sqlite3
• pnpm test

[greptile-apps]

Greptile Summary

This PR consolidates Skills and MCP into a new Library sidebar entry and adds a Prompts tab for managing reusable prompt presets. Prompts are persisted in a dedicated KV store (migrated from appSettings), exposed via a new RPC controller, and surfaced in both the task context bar and create-task modal through a shared popover component.

• Adds PromptLibraryService with seed-from-legacy logic, and wires it into app startup and the RPC router alongside the new Library view and PromptModal.
• Replaces the single hardcoded review-prompt button with a PromptActionsMenu popover that renders all library prompts; prompt clicks now append to existing text via appendInitialConversationText rather than replacing it.
• Removes reviewPrompt from appSettings schema/defaults and migrates existing values to the new store via the legacy importer.

Confidence Score: 5/5

Safe to merge; all changes are additive feature work with no modifications to critical data paths.

The feature is well-scoped — a new KV namespace, a new RPC controller, and new UI components — with no changes to existing storage schemas beyond removing the now-migrated reviewPrompt setting. The migration path is tested and the legacy importer is backward-compatible. The two quality issues noted are both non-blocking: redundant DB operations on every prompt fetch and a brief flicker of the task context bar during the initial async load. Neither causes data loss or incorrect behavior.

src/main/core/prompt-library/service.ts (redundant DB calls after seed) and src/renderer/features/tasks/conversations/context-bar.tsx (async load flicker)

Important Files Changed

Filename	Overview
src/main/core/prompt-library/service.ts	New service managing prompt library persistence and seeding from legacy settings; seedIfNeeded runs 4 DB operations on every getPrompts() call after the initial seed due to missing in-memory guard.
src/renderer/features/tasks/conversations/context-bar.tsx	Migrated from sync settings hook to async usePromptLibrary; prompt actions now gated on async data, causing a brief hide of the entire context bar during the initial fetch.
src/renderer/features/library/prompts/use-prompt-library.ts	Well-implemented TanStack Query hook with optimistic updates and rollback; staleTime of 5 min means no initial data is populated on first mount, contributing to the flicker in consumers.
src/renderer/features/library/library-view.tsx	New Library view shell with tab context; context default is non-null so the useLibraryTab guard never fires (noted in prior review thread).
src/renderer/features/library/prompts/prompt-library-view.tsx	CRUD UI for prompts; delete confirmation present; no differentiation between built-in and user prompts (reset path for review prompt noted in prior review).
src/renderer/features/tasks/conversations/prompt-actions-menu.tsx	New popover component for prompt selection; expandedIds state persists across open/close cycles (noted in prior review); otherwise clean.
src/main/db/legacy-port/importers/settings/importer.ts	Legacy reviewPrompt migration correctly redirected to promptLibraryStore.upsertReviewPrompt; test coverage updated accordingly.

Sequence Diagram

sequenceDiagram
    participant Renderer
    participant RPC
    participant PromptLibraryService
    participant KV as KV Store (prompt-library)
    participant DB as appSettings (legacy)

    Note over PromptLibraryService: App startup
    PromptLibraryService->>KV: get('seedVersion')
    alt "seedVersion < SEED_VERSION"
        PromptLibraryService->>DB: read legacy promptLibrary / reviewPrompt
        PromptLibraryService->>KV: set('prompts', mergedPrompts)
        PromptLibraryService->>KV: set('seedVersion', 1)
        PromptLibraryService->>DB: delete legacy keys
    else already seeded
        PromptLibraryService->>DB: deleteLegacyPromptSettings (no-op)
    end

    Renderer->>RPC: promptLibrary.get()
    RPC->>PromptLibraryService: getPrompts()
    PromptLibraryService->>PromptLibraryService: seedIfNeeded()
    PromptLibraryService->>KV: get('prompts')
    KV-->>Renderer: PromptLibraryPrompt[]

    Renderer->>RPC: promptLibrary.update(prompts)
    RPC->>PromptLibraryService: updatePrompts(prompts)
    PromptLibraryService->>KV: set('prompts', validated)

Loading

Prompt To Fix All With AI

Fix the following 4 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 4
src/main/core/prompt-library/service.ts:20-21
`seedIfNeeded` resets `this.seedPromise` to `null` in `finally`, so every subsequent call to `getPrompts()` (triggered on each React Query cache miss, at most every 5 minutes) re-enters the method and executes a DB read (`seedVersion`) followed by three sequential `DELETE` statements in `deleteLegacyPromptSettings()`. After the initial seed those deletes are no-ops, but the round-trips accumulate. A simple boolean flag (`this.isSeeded`) set after the first successful seed would short-circuit this immediately in memory.

```suggestion
export class PromptLibraryService implements IInitializable {
  private seedPromise: Promise<void> | null = null;
  private isSeeded = false;
```

### Issue 2 of 4
src/main/core/prompt-library/service.ts:51-59
The guard only checks `this.seedPromise` (concurrent de-dup), but after `finally` resets it to `null` every call re-runs the DB logic. Checking `this.isSeeded` first would skip the entire block once the seed has been written.

```suggestion
  private async seedIfNeeded(): Promise<void> {
    if (this.isSeeded) return;
    if (this.seedPromise) return this.seedPromise;

    this.seedPromise = (async () => {
      const seedVersion = await promptLibraryKV.get('seedVersion');
      if ((seedVersion ?? 0) >= PROMPT_LIBRARY_SEED_VERSION) {
        await this.deleteLegacyPromptSettings();
        return;
      }
```

### Issue 3 of 4
src/main/core/prompt-library/service.ts:89-91
Set `this.isSeeded = true` in `finally` so the flag is accurate even after a rejection-then-retry cycle.

```suggestion
    })().finally(() => {
      this.isSeeded = true;
      this.seedPromise = null;
    });
```

### Issue 4 of 4
src/renderer/features/tasks/conversations/context-bar.tsx:55-60
**Context bar flickers during prompt library initial load**

`promptLibrary` now comes from an async RPC query (`usePromptLibrary`). On first render, `data` is `undefined`, so `value` defaults to `[]` and `promptActions.length === 0`. For tasks without a linked issue or open draft comments, the third branch of the early-return is immediately `true`, so the entire bar disappears until the fetch resolves. Previously `reviewPrompt` came from the synchronous settings cache and always had a default value, so the bar rendered immediately. Adding `initialData` or `placeholderData` (e.g. an empty array) to the query — or seeding the React Query cache on app startup — would prevent the transient hide.

_{Reviews (3): Last reviewed commit: "Reseed prompt library after startup data..." | Re-trigger Greptile}

[arnestrickmann]

still need to address the greptile comments @jschwxrz

[jschwxrz]

We should also remove the review prompt from the project settings:

[jschwxrz]

Also now that the prompt library is its own concept now and not part of the project settings anymore, we should not save the review prompts in the app settings KV table. We should either create a new table prompt_presets or store the presets in the regular KV table.

[arnestrickmann]

@greptile

[arnestrickmann]

@greptile review

[arnestrickmann]

[arnestrickmann]

[jschwxrz]

nice!! lgtm