feat(ui): implement responsive player browser experience

PLANS.md

@@ -657,7 +657,7 @@ Complete the authoritative gameplay mechanics and terminal match outcomes.
 
 ## Milestone 008 — Player browser experience
 
-**Status:** `NOT_STARTED`
+**Status:** `IN_PROGRESS`
 
 ### Objective
 
@@ -705,9 +705,57 @@ into the browser.
 
 ### Evidence
 
-Completion evidence is not yet available because this milestone has not
-started. Required evidence includes browser-test output, desktop/mobile visual
-checks, refresh recovery results, and filesystem image size.
+Implementation is complete, but the milestone remains `IN_PROGRESS` until the
+required physical-device and current-stable-browser checks can be run.
+
+- `bash scripts/run_host_tests.sh` completed successfully. The five focused
+  browser tests reported keyboard/swipe direction equivalence, intention-only
+  command envelopes, full replacement of chunked projections without
+  explored-map memory, token-only refresh restoration, and local Russian,
+  accessible, responsive assets. All Milestone 001-007 host regressions passed
+  in the same run. The complete default observer projection remained bounded
+  at 688 chunks with a worst-case maximum of 495 bytes against the 512-byte
+  message limit. A separate AddressSanitizer and UndefinedBehaviorSanitizer run
+  of the changed projection suite passed without findings; leak detection was
+  disabled because the sandbox executes under `ptrace`.
+- `python3 scripts/verify_web_assets.py` reported `web asset reproducibility:
+  PASS` with digest
+  `f321d5bb1b4ad8cfcdf306c5a5e696f3b2b00b54792c727fd639671e585b573d`
+  and a complete compressed payload of 17,100 of 1,572,864 allowed bytes.
+  Source inspection and tests found no remote runtime URL, import, font,
+  framework, analytics, or icon dependency. `node --check web/player.js` and
+  `xmllint --noout web/icons.svg` also completed successfully.
+- `pio run -e esp32-c6-devkitm-1` completed with `[SUCCESS]`, reporting 47,508
+  of 327,680 RAM bytes and 1,005,660 of 2,097,152 application bytes. The
+  independent partition check reported `firmware.bin uses 1006288/2097152
+  bytes in partition factory`. `pio run -e esp32-c6-devkitm-1 --target buildfs`
+  completed with `[SUCCESS]`; the independent partition check reported
+  `littlefs.bin uses 2031616/2031616 bytes in partition littlefs`, with all five
+  gzip assets present in the image.
+- Physical delivery passed after the board re-enumerated as `/dev/ttyACM0`.
+  `pio run -e esp32-c6-devkitm-1 --target upload --upload-port /dev/ttyACM0`
+  and the corresponding `uploadfs` command both completed with `[SUCCESS]` and
+  hash-verified every write. The ESP32-C6FH4 revision 0.2 boot log reported
+  application version `0.8.0`, the unchanged 4 MB partition table,
+  `LittleFS mounted: total=2031616 bytes, used=36864 bytes`, and successful HTTP,
+  WebSocket, and provisioning service startup. The saved station SSID remained
+  `k49`, so the device correctly entered its `maze32-F7B9` fallback AP while the
+  host remained on `Mazda7`; the host network was not changed.
+- A USB readback of the complete LittleFS partition used
+  `/home/sasa/.platformio/penv/bin/python
+  /home/sasa/.platformio/packages/tool-esptoolpy/esptool.py --chip esp32c6
+  --port /dev/ttyACM0 read_flash 0x210000 0x1f0000
+  /tmp/maze32-m008-littlefs-readback.bin`. Both the built image and physical
+  readback had SHA-256
+  `606b98e11cbc479bf11bffa9a38d62ddfebce0689f0e3ebf148521190a032fd5`;
+  `cmp` returned zero, proving byte-for-byte delivery without interrupting the
+  host's internet connection.
+- Live browser validation is blocked. The browser-control runtime returned `No
+  browser is available`, and its browser inventory was empty. Therefore the
+  required visual and interaction passes at `412 x 916`, representative tablet
+  and desktop viewports, and current stable Chrome, Safari, Firefox, and Edge
+  cannot yet be recorded. Milestone 008 must not be marked `COMPLETE` until
+  those browser checks pass. Milestone 009 remains `NOT_STARTED`.
 
 ## Milestone 009 — Observer mode and disconnect recovery