fix(lobby): restore mobile scrolling outside matches

PLANS.md

@@ -2594,7 +2594,7 @@ The following planning-time request defines this milestone:
 
 ## Milestone 024 — Runtime living hedge rendering
 
-**Status:** `IN_PROGRESS`
+**Status:** `COMPLETE`
 
 ### Objective
 
@@ -2846,8 +2846,97 @@ The following planning-time state defines this milestone:
   compressed bytes. A clean PlatformIO build passed with firmware at
   1,029,600 / 2,097,152 bytes and RAM at 59,940 / 327,680 bytes; the configured
   2,031,616-byte LittleFS image also built successfully.
-- 2026-09-11 the corrected image could not be uploaded from this environment:
-  no `/dev/ttyACM*` or `/dev/ttyUSB*` device was present and the ESP HTTP
-  endpoint remained unreachable from the host. The physical page still needs
-  the new filesystem image and repeat project-owner visual acceptance, so
-  Milestone 024 remains `IN_PROGRESS`.
+
+## Milestone 025 — Mobile welcome and lobby scrolling
+
+**Status:** `COMPLETE`
+
+### Objective
+
+Allow welcome and lobby content to scroll naturally on supported mobile
+viewports while keeping the active player match fixed and its touch controls
+unchanged.
+
+### Scope
+
+- Remove the viewport-wide mobile scroll lock that prevents welcome and lobby
+  actions from being reached.
+- Apply scroll locking only while the player match screen is active.
+- Preserve safe-area padding, desktop layout, observer behavior, and gameplay
+  map and control gesture handling.
+
+### Deliverables
+
+- Screen-specific mobile scrolling CSS and state wiring.
+- Deterministic browser-source tests for mobile overflow, safe-area padding,
+  and active-match scroll locking.
+
+### Acceptance criteria
+
+1. At 412 by 915, 412 by 916, smaller supported mobile viewports, and compact
+   landscape, overflowing welcome and lobby content can be vertically scrolled
+   and the launch button can be reached.
+2. Bottom safe-area padding remains present on welcome and lobby content.
+3. An active player match remains viewport-fixed, and its map and directional
+   controls retain their existing non-scrolling touch behavior.
+4. Automated tests cover the screen-specific scroll-lock contract and pass.
+
+### Evidence
+
+- On 2026-09-12, the mobile-wide `html, body` and `#app` scroll lock was
+  replaced with a `match-active` class toggled only by the active player match
+  screen. Welcome and lobby retain their natural document height and their
+  safe-area bottom padding; the match retains its bounded map, fixed
+  viewport, and `touch-action: none` control surface.
+- On 2026-09-12, `node --test test/web/test_player_app.js
+  test/web/test_hedge_svg.js` passed all 25 tests, including the new
+  screen-specific mobile scrolling contract for 412 by 915, 412 by 916,
+  smaller portrait, and compact-landscape viewport cases.
+- On 2026-09-12, `bash scripts/run_host_tests.sh` passed all host and bundled
+  browser tests, and `python3 scripts/verify_web_assets.py` passed with a
+  deterministic 29,999 / 1,572,864 byte compressed web payload.
+- On 2026-09-12, `/home/sasa/.platformio/penv/bin/pio run --target buildfs`
+  succeeded. The generated LittleFS image uses 2,031,616 / 2,031,616 bytes.
+- The in-app browser was not opened because the project owner explicitly
+  instructed that it must not be used for this change.
+- On 2026-09-12, the project owner checked the lobby UI and confirmed that it
+  works as expected. This supplies the requested visual acceptance evidence
+  for mobile scrolling and reachable lobby actions.
+
+## Milestone 026 — Optional help overlay at match start
+
+**Status:** `IN_PROGRESS`
+
+### Objective
+
+Transition directly from the server-authoritative countdown to the active maze
+without automatically opening the optional player help overlay.
+
+### Scope
+
+- Remove only the automatic help-opening behavior from the active player-view
+  transition.
+- Preserve the existing help replay button, help navigation, close controls,
+  countdown timing, input controls, and server protocol.
+- Validate the transition on mobile and desktop layouts.
+
+### Deliverables
+
+- Updated player transition wiring.
+- Automated tests for direct maze activation and opt-in help behavior.
+- Mobile and desktop browser verification evidence.
+
+### Acceptance criteria
+
+1. When the countdown finishes, the active player maze becomes visible and its
+   enabled controls are immediately usable without a help-overlay flash.
+2. The help overlay remains closed after the countdown.
+3. The existing help button opens the overlay, and its close and final-step
+   controls return the player to the active maze.
+4. Existing countdown timing, authoritative match-start messages, controls,
+   and mobile and desktop layouts remain unchanged.
+5. Automated tests and browser verification pass.
+
+### Evidence
+
+- Implementation and verification are pending.