ci(mac): make Playwright screenshots best-effort + 90s timeout

Run 25494399543 / job 74810247593 progressed past the change-password
flow + composer-mount + default_models[0] check (so commits d35bf6a
and fdf7f94's Chromium fixes are working) but then crashed on
`shoot('03b-default-model-button')` with:

  playwright._impl._errors.TimeoutError:
    Page.screenshot: Timeout 30000ms exceeded.
  Call log:
    - taking page screenshot
    - waiting for fonts to load...
    - fonts loaded

Page.screenshot waits for the page's webfonts to be resolved before
snapshotting. On macos-14 free runners under --single-process
Chromium, font loading for the Studio chat page (Inter / Geist Mono)
crowds the 30s default. Two changes:

1. Bump screenshot timeout to 90_000ms.
2. Wrap shoot() in try/except. Screenshots are diagnostic artifacts
   uploaded for human triage; a failure to capture one should never
   fail the test. The actual UI assertions live in step()/info()/
   wait_for() calls, which are unaffected.

Adds animations='disabled' for deterministic captures (frozen CSS
transitions). Both playwright_chat_ui.py and playwright_extra_ui.py
get the same treatment.

tests/studio/playwright_chat_ui.py

@@ -220,11 +220,25 @@ with sync_playwright() as p:
     )
 
     def shoot(name):
+        # Screenshots are diagnostic artifacts only -- never fail the
+        # test on a screenshot timeout. Page.screenshot waits for
+        # webfonts to fully load before snapshotting; on macos-14 free
+        # runners with --single-process Chromium, font loading on the
+        # Studio chat page (Inter / Geist Mono) regularly crowds the
+        # 30s default and crashes Page.screenshot. Bump the timeout
+        # AND wrap in try/except so the test progresses even if the
+        # screenshot can't be captured. animations='disabled' freezes
+        # any in-flight CSS transitions for a deterministic snap.
         _n[0] += 1
-        page.screenshot(
-            path = str(ART / f"{_n[0]:02d}-{name}.png"),
-            full_page = True,
-        )
+        try:
+            page.screenshot(
+                path = str(ART / f"{_n[0]:02d}-{name}.png"),
+                full_page = True,
+                timeout = 90_000,
+                animations = "disabled",
+            )
+        except Exception as _shoot_err:
+            info(f"WARN: screenshot {name} failed: {_shoot_err}")
 
     # ─────────────────────────────────────────────────────
     # 1. Change-password through the UI ("Setup your account").

tests/studio/playwright_extra_ui.py

@@ -159,11 +159,19 @@ with sync_playwright() as p:
     page.on("pageerror", _on_pageerror)
 
     def shoot(name: str) -> None:
+        # See playwright_chat_ui.py:shoot -- screenshots are diagnostic,
+        # never fail the test on a font-load timeout under
+        # --single-process Chromium on macos-14 free runners.
         _n[0] += 1
-        page.screenshot(
-            path = str(ART / f"{_n[0]:02d}-{name}.png"),
-            full_page = True,
-        )
+        try:
+            page.screenshot(
+                path = str(ART / f"{_n[0]:02d}-{name}.png"),
+                full_page = True,
+                timeout = 90_000,
+                animations = "disabled",
+            )
+        except Exception as _shoot_err:
+            info(f"WARN: screenshot {name} failed: {_shoot_err}")
 
     # ─────────────────────────────────────────────────────
     # Setup: change-password through the UI + model load.