[LeonardSEO]

What this PR does

Adds a Milestones card under the streak card in Settings on Android and macOS/iOS: eight milestones unlocked on the first day the user's own stored metrics reach them, with the unlock date and a NEW tag for the last 7 days.

• First scored day, 7-day streak, 30-day streak, 100 scored days (a scored day has a Charge value)
• Charge 90 %+, 8 hours asleep, Effort 18+, 10,000 steps

Streaks are consecutive civil days with a score; same-day duplicates count once. Values outside each metric's plausible range never unlock anything.

Pure math in Achievements (StrandAnalytics) with a Kotlin twin and mirrored fixtures. Display-only. No celebration screen.

The official app's achievements are server-driven; this is a local equivalent.

Type of change

• New feature

How it was tested

• AchievementsTests / AchievementsTest (same fixtures: streak unlock day, gaps reset the run, same-day duplicates count once, threshold milestones, implausible rows ignored, NEW window).
• swift test in Packages/StrandAnalytics: 2145 tests pass.
• ./gradlew testFullDebugUnitTest: 6690 tests, all pass apart from the 2 RecoveryDriversTest half-tie cases that fail the same way on unmodified main.
• Tools/i18n_audit.py --ci, Tools/doc_comment_lint.py, docs/protocol-examples checks and Tools/parity_ledger.py --refresh-derived (derived snapshots included): pass.
• Tools unit tests, the parity acceptance suite and the R-R contract: pass apart from the 4 test_check_source_references cases (/var vs /private/var temp path on macOS) that fail the same way on unmodified main.
• Apple: the macOS app (Strand) builds with this change on my development branch; StrandTests and the iOS target were not run locally for this branch. app-build.yml covers both.

Checklist

• Swift package tests pass for any package I touched
• Android unit tests pass if I touched android/ (apart from the 2 RecoveryDriversTest half-tie cases that fail the same way on unmodified main)
• No new build warnings introduced (Android: none; Apple warnings not checked per branch)
• UI changes use only StrandDesign / Palette / Metrics tokens
• No hardcoded hex frame bytes; protocol facts live in the schema / decoders
• Follows the conventions in docs/CONTRIBUTING.md
• I did not commit generated output (Strand.xcodeproj/) or any secrets/keystores

Related issues

Builds on the streak card (#569).

🤖 Generated with Claude Code