feat(stats): add RF and signal analytics

[n30nex]

Adds the RF / Signal analytics page with SNR/RSSI distributions, hourly means, sample availability and exact tables. It uses the region selector and 24h/7d/30d ranges, keeps missing readings explicit and gives the tab its own waveform icon. The displayed window explains complete-hour background snapshots.

Depends on #59 and server MeshCore-Beacon/beacon-server#157. The server endpoint must be merged and deployed before this page lands. Closes #54.

Validation: current-head build/lint/tests and CI pass; the combined Pi build passes all 781 tests. The actual public page reports LIVE and displays reconciled real data with the new server. Earlier histogram, missing-data, theme and responsive tests remain in place; the new text/icons passed browser checks at 390/1280px. Upstream web CodeQL is still skipped under its existing policy.

Focused change: n30nex/beacon-web-contributions@3fec892...80dad50

[n30nex]

@MrAlders0n — ready for your / Claude review of b138e59. This adds the RF / Signal page with five charts and exact tables. The focused diff is linked in the PR body; it remains a dependent draft after #53 and server #157.

Build/tests pass on the actual head; the combined Pi build passes all 772 tests. Browser checks covered 320/390/768/1280px, themes, regional and 30-day views, single-hour data, missing samples, and error/empty/retry states. The live Pi page uses real data and retains the previous analytics work and #49. #54 is linked for closure when this complete page scope merges. The disabled upstream web CodeQL job and physical Safari gap remain explicit.

[n30nex]

@MrAlders0n - please review this PR with your Claude agent when available. It is now out of draft at n30nex's request. Current head: f97d4023.

Review/merge order: #52 -> #53 -> #55 -> #57. Dependencies remain explicit even though all PRs are ready for review. The shared roadmap and contributor workflow are available in docs PR #5. The new Paths & Hashes page is live on the Pi preview, with matching source/changelog.

GitHub denied formal reviewer assignment for this account, so this comment is the review request.

[MrAlders0n]

Holding this one for now — not on the frontend work, which looks fine.

/stats/signal does not exist on beacon-server yet: server #157 is still open, so dev is at 951b79b without it. Merging this now would put a permanently erroring RF / Signal tab on both deployments. It degrades gracefully (retry: false plus the role="alert" line, which is the right call), but it would still be a visibly broken tab.

Unblocking order: server #157 merges → gets deployed → this lands.

Also: #53 is now in as e01c090, which includes #52. This branch will need a rebase onto the new dev before it can go in.

[n30nex]

@MrAlders0n — refreshed onto the accepted #53/#52 squash, with the independent icon fix #59 below it. Current head 80dad500 passes CI and has its own waveform glyph plus complete-hour snapshot text. The combined Pi build passes all 781 tests; the public Signal page is LIVE with reconciled data.

Your deployment hold is retained: server #157 must merge and be deployed before this page lands. The focused diff and current dependencies are in the body. Ready for your / Claude recheck.