feat: add My Atlas saved node monitoring (post-2.0)

[n30nex]

My Atlas saves up to twelve nodes by full public key, their order and a 24h/3d sample window in this browser. Compact cards show reception bars and signal meters, with Heard by and statistics on demand. It reuses the upstream inspection panels and needs no new backend or database schema.

Closes #96. Draft: hold until after the stable 2.0 release. The feature is refreshed on web dev 39e921c (hourly rollups), preserving the existing PR history without a force push. My Atlas is first on desktop and mobile. Topology remains a separate post-release feature.

The focused Atlas commit is d1eb973; this PR has the identical source tree. Standalone build and 36 focused tests passed. The combined experimental source also passed native Node 24.15.0 build/lint and all 1,180 tests, plus desktop/French phone browser checks. Exact PR-head CI is tracked below by GitHub.

Post-2.0 merge sequence and validation. The current Pi preview is unchanged; the prepared 2.0 pair requires a separate database/history cutover decision. No review request accompanies this refresh.

[n30nex]

@MrAlders0n — My Atlas is ready for your / Claude's review as the one feature PR requested. It follows #95; the focused parent-to-head diff is in the description, and earlier PRs did not need rebasing.

The Pi preview now runs this exact head, 4fd4b0de, with the existing server and review candidates. It saves the selected nodes/order locally, keeps the cards compact, and expands Heard by only when needed. The labels explicitly describe a retained report sample, not a complete traffic total; companions' identified-origin requests count too.

Windows and native Pi build/lint/all 960 tests pass. Published-head CI passes (CodeQL skipped); desktop/French phone, keyboard, reload, ordering/removal, observer dashboard Back and packet links were checked. All 19 public assets and the source/changelog match, with no service restart. The previous frontend is preserved for rollback.

The roadmap and release handoff are updated in existing docs #5. #96 remains open until acceptance; this PR carries its closing reference. Production release stays with you.

[n30nex]

@MrAlders0n / Claude: Atlas is refreshed at 66ae0cc2 after the 1.3.2 release cut (#99). Please keep it out of 1.3.2 and review it for the following phase.

The marked storage paragraph is removed in both languages and the tab now follows Observers. Windows/Pi build, lint and all 975 tests pass, as does current-head build CI (web CodeQL skipped). Saved cards, Heard by and the observer-dashboard return flow pass browser checks. The live Pi stays on release eb241ca7 without Atlas; this branch was tested separately.

The focused diff and release/recovery record are in the updated description. No merge or release tag was performed.