diff --git a/AGENTS.md b/AGENTS.md
index e772c0e7..37a36292 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -1,42 +1,16 @@
 # Repository Guidelines
 
-## Project Structure & Module Organization
+Canonical agent/contributor guidance for this repository lives in [CLAUDE.md](CLAUDE.md) —
+project structure, build/test/lint commands, code style, testing safety rules
+(never run the full suite inside a managed tmux session), security notes, and
+the deployment workflow are all maintained there. Please read it before making
+changes, and keep it the single source of truth rather than duplicating
+sections here.
 
-Codeman is a TypeScript ESM Node project. Core backend code lives in `src/`, with web routes in `src/web/routes/`, web server wiring in `src/web/`, config in `src/config/`, shared types in `src/types/`, and utilities in `src/utils/`. Browser assets are plain JavaScript/CSS under `src/web/public/`. Tests live in `test/`, with route tests in `test/routes/`, mobile Playwright/Vitest tests in `test/mobile/`, and mocks in `test/mocks/`. The standalone xterm local-echo package lives in `packages/xterm-zerolag-input/`; behavior copied into the web UI must stay in sync. Documentation and plans are in `docs/`, scripts in `scripts/`, and build/lint/test config in `config/`.
+Quick pointers:
 
-## Build, Test, and Development Commands
-
-- `npm run dev`: start the local web app via `tsx src/index.ts web`.
-- `npm run build`: build production output into `dist/` using `scripts/build.mjs`.
-- `npm run start`: run the built CLI/web app from `dist/index.js`.
-- `npm run typecheck`: run `tsc --noEmit`.
-- `npm run lint` / `npm run lint:fix`: check or fix TypeScript lint issues.
-- `npm run format:check` / `npm run format`: check or apply Prettier formatting.
-- `npm run check:lockfile`: verify workspace lockfile sync.
-
-## Coding Style & Naming Conventions
-
-Use TypeScript with strict compiler settings and ESM imports only; avoid `require()`. Prettier uses single quotes, trailing commas where valid, and a 120-column print width. ESLint allows `console`, errors on `debugger`, and warns on explicit `any`. Prefer domain-specific files such as `src/web/routes/*-routes.ts`, `src/types/*.ts`, and `src/config/*.ts`; import config from specific files rather than barrels. Keep route handlers schema-validated with Zod where request input is accepted.
-
-## Testing Guidelines
-
-Vitest is the primary test framework. Do not run bare `npm test` in managed Codeman/tmux sessions because the full suite can spawn and clean up tmux sessions. Prefer targeted runs:
-
-```bash
-npm test -- test/routes/session-routes.test.ts
-npm test -- -t "auth"
-```
-
-Route tests should use `app.inject()` instead of live ports. When adding tests that need ports, search for existing `const PORT =` values and choose a unique one. Coverage is available with `npm run test:coverage`.
-
-## Commit & Pull Request Guidelines
-
-Recent history uses Conventional Commit-style messages such as `feat(web): ...`, `fix: ...`, `docs: ...`, and `chore: version packages`. Keep commits scoped and descriptive. Pull requests should include the problem, the approach, linked issues when available, and screenshots or screen recordings for UI/mobile changes. Before opening a PR, run `npm run typecheck`, `npm run lint`, `npm run format:check`, `npm run check:lockfile`, and relevant targeted tests.
-
-## Branch Workflow
-
-Do not develop new features or bug fixes directly on `master`. Start from an up-to-date `master`, create a focused branch such as `fix/mobile-toolbar-overlap` or `feat/session-search`, commit there, then merge or open a pull request after verification. Keep uncommitted work on the branch until it is ready to integrate.
-
-## Security & Configuration Tips
-
-Do not commit secrets or local state from `~/.codeman/`. Auth and CLI behavior are controlled through environment variables such as `CODEMAN_USERNAME`, `CODEMAN_PASSWORD`, `CLAUDE_CODE_*`, and `OPENCODE_*`; validate new settings through the existing schemas and prefix allowlists.
+- Type check: `tsc --noEmit` · Lint: `npm run lint` · Format: `npm run format:check`
+- Targeted tests only: `npm test -- test/<file>.test.ts` (bare `npm test` is unsafe in managed sessions)
+- Route tests use `app.inject()`; new tests needing ports must pick a unique `const PORT =`
+- Branch off `master` for all work; Conventional Commit-style messages (`fix(mobile): ...`)
+- Never commit secrets or local state from `~/.codeman/`
diff --git a/src/session.ts b/src/session.ts
index c7e9084b..5362f9e4 100644
--- a/src/session.ts
+++ b/src/session.ts
@@ -2052,17 +2052,43 @@ export class Session extends EventEmitter {
   private _ptyCols = 120;
   private _ptyRows = 40;
 
+  /**
+   * Live WebSocket connections that have announced a desktop viewport for this
+   * session. While at least one is registered, small-viewport (mobile/tablet)
+   * resizes are ignored so a phone glancing at the session can't reflow the
+   * PTY under an active desktop view. Claims are connection-scoped: ws-routes
+   * registers them on a desktop-typed resize and releases them on socket
+   * close, so a mobile-only session (no desktop connected) keeps full control
+   * of its own size — including narrowing below the spawn default.
+   */
+  private _desktopSizeClaims = new Set<symbol>();
+
+  /** Register a live desktop sizing claim (see _desktopSizeClaims). */
+  claimDesktopSizing(token: symbol): void {
+    this._desktopSizeClaims.add(token);
+  }
+
+  /** Release a desktop sizing claim when its connection goes away. */
+  releaseDesktopSizing(token: symbol): void {
+    this._desktopSizeClaims.delete(token);
+  }
+
   /**
    * Resizes the PTY terminal dimensions.
    * Skips the resize if dimensions haven't changed to avoid triggering
    * unnecessary Ink full-screen redraws (visible flicker on tab switch).
    *
+   * Arbitration: while a desktop connection holds a sizing claim, resizes from
+   * small viewports (mobile/tablet) are ignored entirely — shrink AND grow
+   * would both reflow the desktop view. Without a desktop connected, small
+   * viewports control the PTY size freely.
+   *
    * @param cols - Number of columns (width in characters)
    * @param rows - Number of rows (height in lines)
    */
   resize(cols: number, rows: number, options: { viewportType?: ResizeViewportType } = {}): void {
     const isSmallViewport = options.viewportType === 'mobile' || options.viewportType === 'tablet';
-    if (isSmallViewport && cols < this._ptyCols) {
+    if (isSmallViewport && this._desktopSizeClaims.size > 0) {
       return;
     }
     if (this.ptyProcess && (cols !== this._ptyCols || rows !== this._ptyRows)) {
diff --git a/src/web/public/index.html b/src/web/public/index.html
index a9087772..438845bb 100644
--- a/src/web/public/index.html
+++ b/src/web/public/index.html
@@ -77,7 +77,11 @@
       <div class="session-tabs" id="sessionTabs" role="tablist" aria-label="Session tabs">
       </div>
 
+      <!-- Detached single-session window title (shown only in solo mode) -->
+      <div class="solo-session-title" id="soloSessionTitle" style="display: none;" aria-live="polite"></div>
+
       <div class="header-right mobile-collapsed" id="headerRight">
+        <button class="btn-icon-header btn-solo-redock" id="soloRedockBtn" style="display: none;" onclick="window.close()" title="Re-dock to dashboard (close window)" aria-label="Re-dock session to dashboard">&#x229E;</button>
         <button class="tunnel-indicator" id="tunnelIndicator" style="display: none;" onclick="app.toggleTunnelPanel()" title="Cloudflare Tunnel" aria-label="Tunnel status">
           <span class="tunnel-dot"></span>
         </button>
diff --git a/src/web/public/mobile-handlers.js b/src/web/public/mobile-handlers.js
index 827ed4c4..08f4c452 100644
--- a/src/web/public/mobile-handlers.js
+++ b/src/web/public/mobile-handlers.js
@@ -434,10 +434,13 @@ const KeyboardHandler = {
         const cols = Math.max(dims.cols, 40);
         const rows = Math.max(dims.rows, 10);
         app._lastResizeDims = { cols, rows };
+        // Declare the viewport type so resize arbitration can ignore this
+        // while a desktop connection is sizing the same session.
+        const viewportType = MobileDetection.getDeviceType ? MobileDetection.getDeviceType() : 'mobile';
         fetch(`/api/sessions/${app.activeSessionId}/resize`, {
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({ cols, rows }),
+          body: JSON.stringify({ cols, rows, viewportType }),
         }).catch(() => {});
       }
     } catch {}
diff --git a/src/web/public/styles.css b/src/web/public/styles.css
index a253aedf..1b9198da 100644
--- a/src/web/public/styles.css
+++ b/src/web/public/styles.css
@@ -190,6 +190,12 @@ body {
   filter: brightness(1.1);
 }
 
+/* Mobile-only header utility toggle — hidden by default; the mobile/tablet
+   media queries in mobile.css (max-width: 768px) re-enable it as flex. */
+.mobile-header-utility-toggle {
+  display: none;
+}
+
 /* Session Tabs */
 .session-tabs {
   display: flex;
diff --git a/src/web/routes/ws-routes.ts b/src/web/routes/ws-routes.ts
index c22931ef..b32e7fb2 100644
--- a/src/web/routes/ws-routes.ts
+++ b/src/web/routes/ws-routes.ts
@@ -109,6 +109,12 @@ export function registerWsRoutes(app: FastifyInstance, ctx: SessionPort, getHost
       socket.send(`{"t":"o","d":${JSON.stringify(DEC_2026_START + data + DEC_2026_END)}}`);
     };
 
+    // Per-connection desktop sizing claim — registered on the first
+    // desktop-typed resize and released on socket close, so Session.resize()
+    // can ignore small-viewport resizes only while a desktop is actually
+    // connected (see Session._desktopSizeClaims).
+    const sizingToken = Symbol('ws-desktop-sizing');
+
     // Attach message handler synchronously BEFORE any async work
     // (@fastify/websocket requirement to avoid dropped messages).
     socket.on('message', (raw) => {
@@ -127,6 +133,13 @@ export function registerWsRoutes(app: FastifyInstance, ctx: SessionPort, getHost
           msg.r <= 200
         ) {
           const viewportType = msg.v === 'mobile' || msg.v === 'tablet' || msg.v === 'desktop' ? msg.v : undefined;
+          if (viewportType === 'desktop') {
+            session.claimDesktopSizing(sizingToken);
+          } else if (viewportType) {
+            // The connection's viewport can change (e.g. browser window
+            // narrowed past the tablet breakpoint) — drop a stale claim.
+            session.releaseDesktopSizing(sizingToken);
+          }
           if (viewportType) {
             session.resize(msg.c, msg.r, { viewportType });
           } else {
@@ -210,6 +223,7 @@ export function registerWsRoutes(app: FastifyInstance, ctx: SessionPort, getHost
       session.off('clearTerminal', onClearTerminal);
       session.off('needsRefresh', onNeedsRefresh);
       session.off('exit', onSessionExit);
+      session.releaseDesktopSizing(sizingToken);
 
       // Decrement per-session connection count
       const count = sessionWsCount.get(id) ?? 1;
diff --git a/test/mobile/snapshots/device-ipad-mini.png b/test/mobile/snapshots/device-ipad-mini.png
index ff26fe40..1935f9ef 100644
Binary files a/test/mobile/snapshots/device-ipad-mini.png and b/test/mobile/snapshots/device-ipad-mini.png differ
diff --git a/test/mobile/snapshots/device-ipad-pro-11.png b/test/mobile/snapshots/device-ipad-pro-11.png
index 67f1e9c9..74c63eac 100644
Binary files a/test/mobile/snapshots/device-ipad-pro-11.png and b/test/mobile/snapshots/device-ipad-pro-11.png differ
diff --git a/test/mobile/snapshots/device-iphone-14-pro.png b/test/mobile/snapshots/device-iphone-14-pro.png
index eb0a2c9b..6192bfde 100644
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diff --git a/test/mobile/snapshots/device-iphone-15-pro-max.png b/test/mobile/snapshots/device-iphone-15-pro-max.png
index 28c7fbb0..66b6fdba 100644
Binary files a/test/mobile/snapshots/device-iphone-15-pro-max.png and b/test/mobile/snapshots/device-iphone-15-pro-max.png differ
diff --git a/test/mobile/snapshots/device-iphone-se.png b/test/mobile/snapshots/device-iphone-se.png
index c1c93693..92993db2 100644
Binary files a/test/mobile/snapshots/device-iphone-se.png and b/test/mobile/snapshots/device-iphone-se.png differ
diff --git a/test/mobile/snapshots/device-nexus-7.png b/test/mobile/snapshots/device-nexus-7.png
index fa426bd6..a21d7d2e 100644
Binary files a/test/mobile/snapshots/device-nexus-7.png and b/test/mobile/snapshots/device-nexus-7.png differ
diff --git a/test/mobile/snapshots/keyboard-1024w.png b/test/mobile/snapshots/keyboard-1024w.png
index 1c51e8b5..cdb34785 100644
Binary files a/test/mobile/snapshots/keyboard-1024w.png and b/test/mobile/snapshots/keyboard-1024w.png differ
diff --git a/test/mobile/snapshots/keyboard-320w.png b/test/mobile/snapshots/keyboard-320w.png
index 23d32283..d279f4d0 100644
Binary files a/test/mobile/snapshots/keyboard-320w.png and b/test/mobile/snapshots/keyboard-320w.png differ
diff --git a/test/mobile/snapshots/keyboard-375w.png b/test/mobile/snapshots/keyboard-375w.png
index 287ac64d..f38c5e26 100644
Binary files a/test/mobile/snapshots/keyboard-375w.png and b/test/mobile/snapshots/keyboard-375w.png differ
diff --git a/test/mobile/snapshots/keyboard-393w.png b/test/mobile/snapshots/keyboard-393w.png
index 84045141..d2bc834e 100644
Binary files a/test/mobile/snapshots/keyboard-393w.png and b/test/mobile/snapshots/keyboard-393w.png differ
diff --git a/test/mobile/snapshots/keyboard-430w.png b/test/mobile/snapshots/keyboard-430w.png
index 6e53423e..a6b079dc 100644
Binary files a/test/mobile/snapshots/keyboard-430w.png and b/test/mobile/snapshots/keyboard-430w.png differ
diff --git a/test/mobile/snapshots/keyboard-768w.png b/test/mobile/snapshots/keyboard-768w.png
index 3f3f7bde..3860e176 100644
Binary files a/test/mobile/snapshots/keyboard-768w.png and b/test/mobile/snapshots/keyboard-768w.png differ
diff --git a/test/mobile/snapshots/landing-1024w.png b/test/mobile/snapshots/landing-1024w.png
index 1935a01e..c9cee544 100644
Binary files a/test/mobile/snapshots/landing-1024w.png and b/test/mobile/snapshots/landing-1024w.png differ
diff --git a/test/mobile/snapshots/landing-320w.png b/test/mobile/snapshots/landing-320w.png
index 2d02b8b5..7ea0e5da 100644
Binary files a/test/mobile/snapshots/landing-320w.png and b/test/mobile/snapshots/landing-320w.png differ
diff --git a/test/mobile/snapshots/landing-375w.png b/test/mobile/snapshots/landing-375w.png
index 0e989655..ea552cec 100644
Binary files a/test/mobile/snapshots/landing-375w.png and b/test/mobile/snapshots/landing-375w.png differ
diff --git a/test/mobile/snapshots/landing-393w.png b/test/mobile/snapshots/landing-393w.png
index e4263012..994213f4 100644
Binary files a/test/mobile/snapshots/landing-393w.png and b/test/mobile/snapshots/landing-393w.png differ
diff --git a/test/mobile/snapshots/landing-430w.png b/test/mobile/snapshots/landing-430w.png
index 91e25760..18c3a6a6 100644
Binary files a/test/mobile/snapshots/landing-430w.png and b/test/mobile/snapshots/landing-430w.png differ
diff --git a/test/mobile/snapshots/landing-768w.png b/test/mobile/snapshots/landing-768w.png
index 7e1e4973..768b4623 100644
Binary files a/test/mobile/snapshots/landing-768w.png and b/test/mobile/snapshots/landing-768w.png differ
diff --git a/test/mocks/mock-session.ts b/test/mocks/mock-session.ts
index cc03e1e5..3677cd9c 100644
--- a/test/mocks/mock-session.ts
+++ b/test/mocks/mock-session.ts
@@ -236,6 +236,10 @@ export class MockSession extends EventEmitter {
   /** Stub for resize */
   resize = vi.fn();
 
+  /** Stubs for the desktop sizing claims used by resize arbitration */
+  claimDesktopSizing = vi.fn();
+  releaseDesktopSizing = vi.fn();
+
   /** Stub for runPrompt */
   runPrompt = vi.fn(async () => {});
 
diff --git a/test/routes/ws-routes.test.ts b/test/routes/ws-routes.test.ts
index eac1e8df..342ae0aa 100644
--- a/test/routes/ws-routes.test.ts
+++ b/test/routes/ws-routes.test.ts
@@ -307,6 +307,33 @@ describe('ws-routes', () => {
       }
     });
 
+    it('claims desktop sizing on a desktop resize and releases it on close', async () => {
+      const ws = await connectWs('/ws/sessions/ws-test-session/terminal');
+      const session = ctx._session;
+      try {
+        ws.send(JSON.stringify({ t: 'z', c: 160, r: 48, v: 'desktop' }));
+
+        await vi.waitFor(() => {
+          expect(session.claimDesktopSizing).toHaveBeenCalledTimes(1);
+        });
+        const token = session.claimDesktopSizing.mock.calls[0][0];
+
+        // A later small-viewport resize on the SAME connection drops the claim
+        // (window narrowed past the breakpoint).
+        ws.send(JSON.stringify({ t: 'z', c: 48, r: 28, v: 'tablet' }));
+        await vi.waitFor(() => {
+          expect(session.releaseDesktopSizing).toHaveBeenCalledWith(token);
+        });
+      } finally {
+        ws.close();
+      }
+
+      // Socket close releases the claim again (idempotent set delete).
+      await vi.waitFor(() => {
+        expect(session.releaseDesktopSizing.mock.calls.length).toBeGreaterThanOrEqual(2);
+      });
+    });
+
     it('accepts resize at minimum bounds (1x1)', async () => {
       const ws = await connectWs('/ws/sessions/ws-test-session/terminal');
       try {
diff --git a/test/session-manager.test.ts b/test/session-manager.test.ts
index 46c0ee38..4fe6ca6f 100644
--- a/test/session-manager.test.ts
+++ b/test/session-manager.test.ts
@@ -81,10 +81,6 @@ vi.mock('../src/session.js', () => {
       return undefined;
     }
 
-    getAttachmentHistoryForPersist() {
-      return undefined;
-    }
-
     getOutput() {
       return 'mock output';
     }
diff --git a/test/session-resize-arbitration.test.ts b/test/session-resize-arbitration.test.ts
index 871950ad..dfa109ec 100644
--- a/test/session-resize-arbitration.test.ts
+++ b/test/session-resize-arbitration.test.ts
@@ -17,21 +17,96 @@ function attachFakePty(session: Session, cols = 160, rows = 48) {
 }
 
 describe('Session resize arbitration', () => {
-  it('ignores mobile resizes that would shrink a wider desktop PTY', () => {
+  it('lets a mobile-only session shrink below the spawn default (no desktop connected)', () => {
     const session = new Session({ workingDir: '/tmp', mode: 'shell' });
     const resize = attachFakePty(session, 160, 48);
 
     session.resize(48, 28, { viewportType: 'mobile' });
 
-    expect(resize).not.toHaveBeenCalled();
+    expect(resize).toHaveBeenCalledWith(48, 28);
   });
 
-  it('allows desktop resizes to change the shared PTY dimensions', () => {
+  it('lets a mobile-only session shrink rows only', () => {
     const session = new Session({ workingDir: '/tmp', mode: 'shell' });
     const resize = attachFakePty(session, 160, 48);
 
+    session.resize(160, 28, { viewportType: 'mobile' });
+
+    expect(resize).toHaveBeenCalledWith(160, 28);
+  });
+
+  it('lets a mobile-only session re-grow after shrinking', () => {
+    const session = new Session({ workingDir: '/tmp', mode: 'shell' });
+    const resize = attachFakePty(session, 160, 48);
+
+    session.resize(48, 28, { viewportType: 'mobile' });
+    session.resize(80, 36, { viewportType: 'tablet' });
+
+    expect(resize).toHaveBeenNthCalledWith(1, 48, 28);
+    expect(resize).toHaveBeenNthCalledWith(2, 80, 36);
+  });
+
+  it('ignores mobile resizes while a desktop connection holds a sizing claim', () => {
+    const session = new Session({ workingDir: '/tmp', mode: 'shell' });
+    const resize = attachFakePty(session, 160, 48);
+    const desktop = Symbol('desktop-conn');
+
+    session.claimDesktopSizing(desktop);
+    session.resize(48, 28, { viewportType: 'mobile' });
+    // Grow is ignored too — it would reflow the desktop view just the same.
+    session.resize(200, 60, { viewportType: 'tablet' });
+
+    expect(resize).not.toHaveBeenCalled();
+  });
+
+  it('always applies desktop resizes, claim or not', () => {
+    const session = new Session({ workingDir: '/tmp', mode: 'shell' });
+    const resize = attachFakePty(session, 160, 48);
+
+    session.claimDesktopSizing(Symbol('desktop-conn'));
     session.resize(120, 40, { viewportType: 'desktop' });
 
     expect(resize).toHaveBeenCalledWith(120, 40);
   });
+
+  it('restores mobile control once the desktop claim is released', () => {
+    const session = new Session({ workingDir: '/tmp', mode: 'shell' });
+    const resize = attachFakePty(session, 160, 48);
+    const desktop = Symbol('desktop-conn');
+
+    session.claimDesktopSizing(desktop);
+    session.resize(48, 28, { viewportType: 'mobile' });
+    expect(resize).not.toHaveBeenCalled();
+
+    session.releaseDesktopSizing(desktop);
+    session.resize(48, 28, { viewportType: 'mobile' });
+    expect(resize).toHaveBeenCalledWith(48, 28);
+  });
+
+  it('keeps ignoring mobile resizes until every desktop claim is released', () => {
+    const session = new Session({ workingDir: '/tmp', mode: 'shell' });
+    const resize = attachFakePty(session, 160, 48);
+    const desktopA = Symbol('desktop-a');
+    const desktopB = Symbol('desktop-b');
+
+    session.claimDesktopSizing(desktopA);
+    session.claimDesktopSizing(desktopB);
+    session.releaseDesktopSizing(desktopA);
+    session.resize(48, 28, { viewportType: 'mobile' });
+    expect(resize).not.toHaveBeenCalled();
+
+    session.releaseDesktopSizing(desktopB);
+    session.resize(48, 28, { viewportType: 'mobile' });
+    expect(resize).toHaveBeenCalledWith(48, 28);
+  });
+
+  it('applies untyped (legacy/API) resizes regardless of claims', () => {
+    const session = new Session({ workingDir: '/tmp', mode: 'shell' });
+    const resize = attachFakePty(session, 160, 48);
+
+    session.claimDesktopSizing(Symbol('desktop-conn'));
+    session.resize(100, 30);
+
+    expect(resize).toHaveBeenCalledWith(100, 30);
+  });
 });