Improve controller connection stability and draw throughput

[Woodii1998]

What changed

• Pre-arm serial ACK/probe waiters before writes, bound serial write/drain time, reject unsafe command batches before execution or persistence, and avoid releasing a timed-out request while its write is still draining.
• Preserve the Bluetooth bond across ordinary resets; reserve virtual-cable unplug for explicit clear-peer, repair 48-byte HID replies and device-address reporting, and keep report counters monotonic.
• Replace permissive firmware numeric parsing with strict full-token parsing and bounded cursor, wait, palette-slot, and color-grid inputs.
• Bound disconnected-component planning above 2,048 components, interleave per-color configuration with drawing, remove redundant palette/official C commands while retaining W 500, and reduce interactive preview scale.
• Persist recovery progress at segment checkpoints using serialized atomic writes; close cleanup/discard/claim races and serialize execution start/resume lifecycle reservations.

Why

The previous implementation had ACK registration and execution-lifecycle check/await races, ordinary resets could discard the host bond, malformed firmware parameters could reach long-running operations, checkerboards entered quadratic component ordering, multicolor plans repeated unnecessary selection commands, and recovery rewrote full JSON on every ACK.

Measured impact

• 256×256 one-color checkerboard planning: 3,576.20 ms → 45.87 ms (about 78× faster).
• Removing redundant selection commands saves an estimated 8.75 minutes at 84 colors and 13.31 minutes at 128 colors with the existing 65/45 ms timing profile.
• Deterministic six-command/two-segment recovery scenario: 8 JSON writes → 4.
• Studio preview requests now default to scale 2; server input is rounded and clamped to 1–4.

Verification

• npm run ci:local:quick — desktop 122/122, flasher 8/8, TypeScript checks and production web build passed.
• /tmp/friendmaker-platformio-venv/bin/platformio run -d firmware/esp32 -e esp32dev_wireless -e esp32dev_wireless_switch2 -e esp32dev_wireless_switch_lite — all three environments passed.
• Focused recovery suite 24/24 and serial/firmware regression suite 22/22 passed during TDD iterations.
• git diff --check fab94c6..HEAD and the credential-pattern scan passed.

Hardware follow-ups

• Verify bond retention for both reset modes and explicit clear-peer timing on physical Switch, Switch Lite, and Switch 2.
• Confirm reply-0x02 Bluetooth-address byte order and conservative congestion/drain behavior under real L2CAP pressure.
• Validate standalone official-color recovery state on hardware.
• This change deliberately keeps W 500, the standard profile's non-waiting send flags, and HID callbacks non-blocking. Truly interruptible long firmware operations and relative palette tracking remain separate HIL work.