diff --git a/.plans/branch-environment-picker-in-chatview-input.md b/.plans/branch-environment-picker-in-chatview-input.md
new file mode 100644
index 0000000000000000000000000000000000000000..2c1994d2c8d6f05995134a7173ae6465e9486178
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+++ b/.plans/branch-environment-picker-in-chatview-input.md
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+# Branch/Environment Picker in ChatView Input
+
+## Summary
+
+Add a secondary toolbar below the ChatView input area (similar to Codex UI) that lets users select the target branch and environment mode (Local vs New worktree) before sending their first message.
+
+## UX
+
+- A toolbar appears **below** the input form (always visible when it's a git repo)
+- Two controls:
+  1. **Environment mode** (left side): toggles between "Local" and "New worktree" — **locked after first message** (no longer clickable, just shows current mode as label)
+  2. **Branch picker** (right side): dropdown showing local branches — **always changeable**, even after messages are sent
+- If not a git repo, the toolbar is hidden entirely (thread uses project cwd as-is)
+
+## Changes
+
+### 0. Install `@tanstack/react-query` in `apps/renderer`
+
+Add dependency + wrap app in `QueryClientProvider`.
+
+### 1. `apps/renderer/src/store.ts` — MODIFY
+
+Add a new action to the reducer:
+
+```ts
+| { type: "SET_THREAD_BRANCH"; threadId: string; branch: string | null; worktreePath: string | null }
+```
+
+Reducer case updates `branch` and `worktreePath` on the thread.
+
+### 2. `apps/renderer/src/components/ChatView.tsx` — MODIFY
+
+**Fetch branches** via `useQuery`:
+
+```ts
+const branchQuery = useQuery({
+  queryKey: ["git-branches", activeProject?.cwd],
+  queryFn: () => api.git.listBranches({ cwd: activeProject!.cwd }),
+  enabled: !!activeProject,
+});
+```
+
+**Local state:**
+
+- `envMode: "local" | "worktree"` — environment mode (local component state)
+
+**UI:** Below the `<form>`, render a toolbar bar (hidden if `!branchQuery.data?.isRepo`):
+
+- Left side: env mode button ("Local" / "New worktree") — disabled after first message (locked in)
+- Right side: branch dropdown from `branchQuery.data.branches`
+- Both styled like existing model picker (small text, chevron, dropdown menus)
+
+**Behavior:**
+
+- Branch picker is always active — changing branch dispatches `SET_THREAD_BRANCH` immediately
+- Env mode is only clickable when `activeThread.messages.length === 0`. After first message, it becomes a static label showing the locked-in mode
+- On first send (`onSend`): if `envMode === "worktree"` and a branch is selected, call `api.git.createWorktree` before starting the session, then dispatch `SET_THREAD_BRANCH` with the worktreePath
+- `ensureSession` already uses `activeThread.worktreePath ?? activeProject.cwd`
+
+### Files to modify
+
+1. `apps/renderer/package.json` — add `@tanstack/react-query`
+2. `apps/renderer/src/main.tsx` (or App entry) — wrap in `QueryClientProvider`
+3. `apps/renderer/src/store.ts` — add `SET_THREAD_BRANCH` action
+4. `apps/renderer/src/components/ChatView.tsx` — branch/env picker UI with `useQuery`
+
+## Verification
+
+1. `turbo build` — compiles
+2. Create a new thread → branch bar appears below input with "Local" + current branch
+3. Change branch in dropdown → branch updates on thread
+4. Toggle "New worktree" → send message → worktree created, session uses worktree cwd
+5. After first message: env mode label locks to "Worktree" (not clickable), branch picker still works
+6. Non-git project → no branch bar shown
diff --git a/.plans/git-flows-integration-tests.md b/.plans/git-flows-integration-tests.md
new file mode 100644
index 0000000000000000000000000000000000000000..70e233a008607fd7ec542c7285ea4a56496aad8c
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+++ b/.plans/git-flows-integration-tests.md
@@ -0,0 +1,99 @@
+# Git Flows Integration Tests
+
+## Overview
+
+Real integration tests that run actual git commands against temporary repos. No mocking.
+
+## Step 1: Extract git functions into `apps/desktop/src/git.ts`
+
+The git functions (`listGitBranches`, `createGitWorktree`, `removeGitWorktree`, `createGitBranch`, `checkoutGitBranch`, `initGitRepo`) and their helper `runTerminalCommand` are currently private in `main.ts`. Extract them into a new `apps/desktop/src/git.ts` module with named exports.
+
+`main.ts` will import and re-use them — no behavior change, just moving code.
+
+**Files modified:**
+
+- `apps/desktop/src/git.ts` — new file with all git functions exported
+- `apps/desktop/src/main.ts` — import from `./git` instead of defining inline
+
+## Step 2: Create `apps/desktop/src/git.test.ts`
+
+Integration tests using real temp git repos. Each test group creates a fresh temp directory with `git init`, makes commits, creates branches as needed, and cleans up after.
+
+### Setup/teardown pattern
+
+```ts
+import { mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import {
+  listGitBranches,
+  createGitBranch,
+  checkoutGitBranch,
+  createGitWorktree,
+  removeGitWorktree,
+  initGitRepo,
+} from "./git";
+
+// Helper: run a raw git command in a dir (for test setup, not under test)
+// Helper: create an initial commit (git needs at least one commit for branches)
+```
+
+### Test groups
+
+**1. initGitRepo**
+
+- Creates a valid git repo in a temp dir
+- listGitBranches reports `isRepo: true` after init
+
+**2. listGitBranches**
+
+- Returns `isRepo: false` for non-git directory
+- Returns the current branch with `current: true`
+- Sorts current branch first
+- Lists multiple branches after creating them
+- `isDefault` is false when no remote (no origin/HEAD)
+
+**3. checkoutGitBranch**
+
+- Checks out an existing branch (current flag moves)
+- Throws when branch doesn't exist
+- Throws when checkout would overwrite uncommitted changes (dirty working tree)
+
+**4. createGitBranch**
+
+- Creates a new branch (appears in listGitBranches)
+- Throws when branch already exists
+
+**5. createGitWorktree + removeGitWorktree**
+
+- Creates a worktree directory at the expected path
+- Worktree has the correct branch checked out
+- Throws when branch is already checked out in another worktree
+- removeGitWorktree cleans up the worktree
+
+**6. Full flow: local branch checkout**
+
+- init → commit → create branch → checkout → verify current
+
+**7. Full flow: worktree creation from selected branch**
+
+- init → commit → create branch → create worktree → verify worktree dir exists and has correct branch
+
+**8. Full flow: thread switching simulation**
+
+- init → commit → create branch-a, branch-b → checkout a → checkout b → checkout a → verify current matches
+
+**9. Full flow: checkout conflict**
+
+- init → commit → create branch → modify file (unstaged) → checkout other branch → expect error
+
+## Verification
+
+```bash
+# Run the git integration tests
+cd apps/desktop && bun run test
+
+# Or just the git test file
+npx vitest run apps/desktop/src/git.test.ts
+```
diff --git a/.plans/git-flows-test-plan.md b/.plans/git-flows-test-plan.md
new file mode 100644
index 0000000000000000000000000000000000000000..45b86b622b5f044a2b6bf373ebb5f3f00fa4e0de
--- /dev/null
+++ b/.plans/git-flows-test-plan.md
@@ -0,0 +1,103 @@
+# Git Flows Test Plan
+
+## Overview
+
+Add tests for git branch/worktree flows. Two files:
+
+1. **Extend** `apps/renderer/src/store.test.ts` — reducer tests for `SET_THREAD_BRANCH`
+2. **Create** `apps/renderer/src/git-flows.test.ts` — flow logic tests
+
+All tests are pure Vitest unit tests (no React rendering). They test the reducer directly and simulate handler logic via sequential reducer dispatches + mocked API calls.
+
+## File 1: `apps/renderer/src/store.test.ts` (extend)
+
+Add `describe("SET_THREAD_BRANCH reducer")` with 6 tests:
+
+- Sets branch + worktreePath atomically
+- Clears both to null
+- Updates branch while preserving worktreePath
+- Does not affect other threads (multi-thread state)
+- No-op for nonexistent thread id
+- Does not mutate messages, error, or session fields
+
+Uses existing `makeThread`, `makeState` factories.
+
+## File 2: `apps/renderer/src/git-flows.test.ts` (new)
+
+### Factories
+
+- `makeThread()`, `makeState()`, `makeSession()` — same pattern as store.test.ts
+- `makeBranch()` — creates `GitBranch` objects
+- `makeMessage()` — creates `ChatMessage` objects
+- `makeGitApi()` — returns `{ checkout, createWorktree, createBranch, listBranches }` with `vi.fn()` mocks
+
+### Test groups (~30 tests total)
+
+**1. Local branch checkout flow** (2 tests)
+
+- Successful checkout → SET_THREAD_BRANCH updates branch
+- Checkout failure → SET_ERROR, branch unchanged
+
+**2. Thread branch conflict on send** (3 tests)
+
+- Two threads maintain independent branch state after SET_ACTIVE_THREAD
+- Branch state preserved through multiple thread switches + updates
+- Checkout failure on thread switch sets error only on target thread
+
+**3. Worktree creation on send** (5 tests)
+
+- First message in worktree mode → createWorktree → SET_THREAD_BRANCH with worktreePath
+- No worktree when messages already exist
+- No worktree in local envMode
+- No worktree when worktreePath already set
+- createWorktree failure → SET_ERROR, send aborted, no messages pushed
+
+**4. Env mode locking** (4 tests)
+
+- envLocked=false when no messages
+- envLocked=true with messages
+- Transitions false→true after PUSH_USER_MESSAGE
+- Remains true after SET_ERROR and UPDATE_SESSION
+
+**5. Auto-fill current branch** (3 tests)
+
+- Dispatches SET_THREAD_BRANCH when thread has no branch and current branch exists
+- Does not overwrite existing branch
+- No-op when no branch is marked current
+
+**6. Default branch detection** (2 tests)
+
+- isDefault flag on branch objects
+- current and isDefault can be on different branches
+
+**7. Branch creation + checkout** (3 tests)
+
+- Successful create + checkout updates branch
+- createBranch failure → error, branch unchanged
+- checkout failure after successful create → error, branch unchanged
+
+**8. Session CWD resolution** (3 tests)
+
+- Uses worktreePath when available
+- cwdOverride takes precedence over worktreePath
+- Falls back to project cwd when no worktree
+
+**9. Error handling patterns** (4 tests)
+
+- SET_ERROR sets error on correct thread
+- SET_ERROR with null clears error
+- Error on one thread doesn't affect others
+- Error cleared before successful branch operations
+
+## Verification
+
+```bash
+# Run all renderer tests
+cd apps/renderer && bun run test
+
+# Run just the new test file
+npx vitest run apps/renderer/src/git-flows.test.ts
+
+# Run just the store tests
+npx vitest run apps/renderer/src/store.test.ts
+```
diff --git a/.plans/git-integration-branch-picker-worktrees.md b/.plans/git-integration-branch-picker-worktrees.md
new file mode 100644
index 0000000000000000000000000000000000000000..b5b5e82e3284091dd9988e6c3cb0c2e691bfc7c5
--- /dev/null
+++ b/.plans/git-integration-branch-picker-worktrees.md
@@ -0,0 +1,115 @@
+# Git Integration: Branch Picker + Worktrees
+
+## Summary
+
+Add git integration to let users start new threads from a specific branch, optionally creating a git worktree for isolated agent work.
+
+## UX Flow
+
+- **Left click** "+ New thread" → immediately creates a thread (current behavior, unchanged)
+- **Right click** "+ New thread" → opens a context menu with git options:
+  - List of local branches → clicking one creates a thread on that branch (uses project cwd)
+  - Each branch has a "worktree" sub-option → creates a worktree, then creates thread with worktree as cwd
+- When thread has a worktree, the agent session uses the worktree path as its cwd
+- If git fails (not a repo), context menu shows "Not a git repository" disabled item
+
+## Changes
+
+### 1. `packages/contracts/src/git.ts` — CREATE
+
+New Zod schemas and types:
+
+- `gitListBranchesInputSchema` — `{ cwd: string }`
+- `gitCreateWorktreeInputSchema` — `{ cwd: string, branch: string, path?: string }`
+- `gitRemoveWorktreeInputSchema` — `{ cwd: string, path: string }`
+- `gitBranchSchema` — `{ name: string, current: boolean }`
+- Result types for each
+
+### 2. `packages/contracts/src/ipc.ts` — MODIFY
+
+- Add 3 IPC channels: `git:list-branches`, `git:create-worktree`, `git:remove-worktree`
+- Add `git` namespace to `NativeApi` with `listBranches`, `createWorktree`, `removeWorktree`
+
+### 3. `packages/contracts/src/index.ts` — MODIFY
+
+- Add `export * from "./git"`
+
+### 4. `apps/desktop/src/main.ts` — MODIFY
+
+Add 3 IPC handlers + helper functions:
+
+- `listGitBranches()` — runs `git branch --no-color`, parses output into `{ name, current }[]`
+- `createGitWorktree()` — runs `git worktree add <path> <branch>`, defaults path to `../{repo}-worktrees/{branch}`
+- `removeGitWorktree()` — runs `git worktree remove <path>`
+
+Reuses existing `runTerminalCommand()`.
+
+### 5. `apps/desktop/src/preload.ts` — MODIFY
+
+Add `git` namespace with 3 `ipcRenderer.invoke` calls.
+
+### 6. `apps/renderer/src/types.ts` — MODIFY
+
+Add to `Thread`:
+
+```
+branch: string | null
+worktreePath: string | null
+```
+
+### 7. `apps/renderer/src/persistenceSchema.ts` — MODIFY
+
+- Add optional `branch`/`worktreePath` to persisted thread schema (`.nullable().optional()` for backwards compat)
+- Add V3 schema, update union
+- Update `hydrateThread` to default new fields to `null`
+- Update `toPersistedState` to serialize new fields
+
+### 8. `apps/renderer/src/store.ts` — MODIFY
+
+- Update persisted state key to v3, keep v2 as legacy fallback
+
+### 9. `apps/renderer/src/components/Sidebar.tsx` — MODIFY (main UI work)
+
+- Keep existing left-click `handleNewThread` unchanged (immediate thread creation)
+- Add `onContextMenu` handler to "+ New thread" buttons (both global and per-project)
+- On right-click: fetch branches via `api.git.listBranches`, show a custom context menu
+- Context menu items: branch names, each with a nested option to create with worktree
+- Clicking a branch → creates thread with `branch` set, title = branch name
+- Clicking "with worktree" → calls `api.git.createWorktree` first, then creates thread with `worktreePath`
+- Show branch badge on thread list items
+- If not a git repo, show "Not a git repository" as disabled menu item
+
+Context menu component: a positioned `<div>` with `position: fixed` anchored to the click position, dismissed on click-outside or Escape. Follows the existing dropdown pattern from ChatView's model picker.
+
+### 10. `apps/renderer/src/components/ChatView.tsx` — MODIFY
+
+- Line 157: use `activeThread.worktreePath ?? activeProject.cwd` as session cwd
+- Show branch/worktree badge in header bar
+
+## Implementation Order
+
+1. `packages/contracts/src/git.ts` (new schemas)
+2. `packages/contracts/src/ipc.ts` + `index.ts` (wire up channels)
+3. `apps/desktop/src/main.ts` (git command handlers)
+4. `apps/desktop/src/preload.ts` (bridge methods)
+5. `apps/renderer/src/types.ts` (Thread type update)
+6. `apps/renderer/src/persistenceSchema.ts` + `store.ts` (persistence migration)
+7. `apps/renderer/src/components/Sidebar.tsx` (branch picker UI)
+8. `apps/renderer/src/components/ChatView.tsx` (worktree cwd + badge)
+
+## Edge Cases
+
+- **Not a git repo**: `git branch` fails → context menu shows "Not a git repository" disabled item
+- **Branch has slashes**: `feature/foo` → worktree dir becomes `feature-foo`
+- **Worktree exists**: git error surfaces to user via inline error message in context menu
+- **No persistence breakage**: `.nullable().optional()` fields parse fine with old data
+
+## Verification
+
+1. `turbo build` — confirm contracts/desktop/renderer all compile
+2. Launch app, add a project pointing to a git repo
+3. Click "+ New thread" → verify branch list loads
+4. Select a branch, click Start → thread created with branch in title
+5. Enable worktree checkbox, pick branch, Start → verify worktree directory created on disk
+6. Send a message in worktree thread → verify agent runs in worktree cwd
+7. Add a non-git project → verify graceful error, can still create thread