[slkass]

Add opt-in rainbow, breathing and rumble-linked lighting with an optional idle fade. Effects respect the existing Light page's brightness, low-battery indication, Light Off and native-mode output opt-in. Hardware changes are paced to 40 Hz.

The controller drawing and touch-feedback color follow the actual LED output. Static color remains the default. This final layer completes the seven-tool Lab and its documentation without changing the previously accepted installed behavior.

Dependencies and focused review

Stacked PR 7/7; depends on #15 and the earlier layers, starting with #9. All targets are upstream main, so GitHub's Files changed view currently includes unmerged dependencies. Review only this feature's incremental diff (commit b8c18c9).

Merge in the order below. Preserve the shared commit ancestry when merging, or rebase the remaining branches after squash/rebase merges so already-merged layers disappear from their diffs.

1. Controller Lab 1/7: DualSense trigger effects and timed trials #10 — DualSense trigger effects and timed trials
2. Controller Lab 2/7: touchpad mouse and trackball #11 — touchpad mouse and trackball
3. Controller Lab 3/7: Flick Stick and gyro mouse aiming #12 — Flick Stick and gyro mouse aiming
4. Controller Lab 4/7: Hair Trigger, two-stage pulls and Hip Fire #13 — Hair Trigger, two-stage pulls and Hip Fire
5. Controller Lab 5/7: configurable button debounce #14 — configurable button debounce
6. Controller Lab 6/7: local DSU motion forwarding #15 — local DSU motion forwarding
7. Controller Lab 7/7: dynamic lighting and matching touch feedback #16 — dynamic lighting and matching touch feedback

Validation

• cargo fmt --all --check
• cargo clippy --workspace --all-targets --release --locked -- -D warnings
• cargo test --workspace --locked: 275 passed, 5 driver/manual tests ignored, zero failures (Windows x64).
• DualSense hardware: rainbow and breathing effects confirmed by the tester. Unit tests cover configuration bounds and idle fade. The final source tree is verified identical to the hardware-tested Controller Lab implementation (37b059a).

All new tools are disabled by default. No additional dependencies are added. Cross-platform CI results are reported by GitHub checks.