D6: AI Director polish + parity hardening

- pf2e parity: a unit test confirms the director carries the system through
  (systemConstraint + prompt say Pathfinder 2e, no cross-system leak) and still
  produces a grounded deterministic turn. (Degree-of-success/conditions already
  branch per system via the shared kernel.)
- UX: the transcript pane is now a bounded, scrollable region (max-h-[60vh]) so
  long sessions don't blow the page layout; it still auto-scrolls to the newest line.
- e2e: e2e/director.spec.ts exercises the full flow against a real browser — DM
  narrates a grounded scene with no API key (deterministic badge, empty-state
  clears, Continue appears), and the player persona seats a party character and
  takes a turn.

396 unit tests + 2 director e2e green; lint clean; build OK.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

e2e/director.spec.ts

@@ -0,0 +1,44 @@
+import { test, expect } from '@playwright/test';
+
+test.beforeEach(async ({ page }) => {
+  await page.goto('/');
+  await page.evaluate(async () => {
+    indexedDB.deleteDatabase('ttrpg-manager');
+    localStorage.clear();
+  });
+  await page.reload();
+  // Load the sample campaign (gives us a party + an active encounter).
+  await page.getByLabel('Settings').click();
+  await page.getByRole('button', { name: 'Load sample campaign' }).click();
+  await expect(page.getByRole('heading', { name: 'Sample: Lost Mine' })).toBeVisible();
+});
+
+test('AI Director narrates a grounded scene with no API key (deterministic)', async ({ page }) => {
+  await page.getByLabel('Primary').getByRole('link', { name: 'AI Director' }).click();
+  await expect(page.getByRole('heading', { name: 'AI Director' })).toBeVisible();
+  await expect(page.getByText(/deterministic mode/)).toBeVisible();
+
+  // Empty until we start.
+  await expect(page.getByText('The story begins when you start the scene.')).toBeVisible();
+
+  await page.getByRole('button', { name: 'Begin the scene' }).click();
+
+  // A narration entry appears; the empty-state is gone; source badge shows deterministic.
+  await expect(page.getByText('The story begins when you start the scene.')).toBeHidden();
+  await expect(page.getByText('deterministic', { exact: true })).toBeVisible();
+  await expect(page.getByRole('button', { name: 'Continue' })).toBeVisible();
+});
+
+test('the director can play a chosen party character (player persona)', async ({ page }) => {
+  await page.getByLabel('Primary').getByRole('link', { name: 'AI Director' }).click();
+
+  await page.getByRole('button', { name: 'Player', exact: true }).click();
+  // Subtitle reflects the mode.
+  await expect(page.getByText(/· Player/)).toBeVisible();
+
+  // Seat the AI on the first party character.
+  await page.getByLabel('Character the AI plays').selectOption({ index: 1 });
+
+  await page.getByRole('button', { name: /Take the first action|Take turn/ }).click();
+  await expect(page.getByText('deterministic', { exact: true })).toBeVisible();
+});

src/features/assistant/director/TranscriptPane.tsx

@@ -18,7 +18,7 @@ export function TranscriptPane({ entries }: { entries: DirectorTranscriptEntry[]
   }
 
   return (
-    <div className="space-y-3">
+    <div className="max-h-[60vh] space-y-3 overflow-y-auto pr-1">
       {entries.map((e) => (
         <TranscriptLine key={e.id} entry={e} />
       ))}

src/lib/assistant/director/director.test.ts

@@ -191,6 +191,23 @@ describe('AI Player (player persona)', () => {
     expect(me.resources?.map((r) => r.name)).toContain('Channel Divinity');
   });
 
+  it('works for a Pathfinder 2e campaign (system carried through, no cross-system leak)', () => {
+    const campaignPf2e: Campaign = { id: 'c2', name: 'Crypt', system: 'pf2e', description: '', createdAt: 't', updatedAt: 't' };
+    const pf2ePc = characterSchema.parse({
+      id: 'pf-Kar', campaignId: 'c2', system: 'pf2e', kind: 'pc', name: 'Kara', className: 'Fighter', level: 3,
+      abilities: { str: 16, dex: 12, con: 14, int: 10, wis: 11, cha: 10 }, hp: { current: 40, max: 40, temp: 0 },
+      createdAt: 't', updatedAt: 't',
+    });
+    const s = buildDirectorScene({ campaign: campaignPf2e, characters: [pf2ePc], persona: 'dm', transcriptWindow: [] });
+    expect(s.system).toBe('pf2e');
+    expect(s.systemConstraint.toLowerCase()).toContain('pathfinder');
+    const { system } = buildDirectorPrompt(s);
+    expect(system.toLowerCase()).toContain('pathfinder');
+    // a deterministic turn is still produced and grounded to the party
+    const t = fallbackDirectorTurn(s);
+    expect(t.narration.length).toBeGreaterThan(0);
+  });
+
   it('prompts in first person as the controlled character and cues its turn', () => {
     const s = buildDirectorScene({ campaign: campaign5e, characters: [caster()], persona: 'player', controlledCharacterId: 'pc-Mira', transcriptWindow: [] });
     const { system } = buildDirectorPrompt(s);