Reuse Trends calendar dates and heat-strip identities

[AlexSchmidt1999]

What this PR does

Trends reparses calendar dates when unrelated repository publications redraw the screen. The existing resolved-metric cache now holds the recovery calendar too, with the same data, range, day, and locale invalidation.

Heat-strip days and weeks use dates as IDs instead of new UUIDs on each reconstruction. Scores and calendar layout stay the same.

Type of change

• Refactor / cleanup

How it was tested

The macOS app and iOS Release builds passed on this PR head. Source hygiene and iOS translation checks passed too. StrandDesign tests passed with the pre-existing English-only recovery-word test skipped on this German host.

The change addresses calendar/date work observed in the local Trends trace.

Checklist

• Generated projects, build output, and credentials are excluded.
• No new dependencies or destructive strap commands.

iPhone follow-up, October 16

The combined build with the calendar cache and stable heat-strip IDs is running on the owner's iPhone. The owner reports that it looks smoother in everyday use.

The anonymized Today measurements from the combined fixes record 1 late callback out of 3,873 (0.026%) over 64.71 seconds, compared with 0.536% over 860.79 seconds before the day-cycle scheduling change. The worst callback interval falls from 159.6 to 63.4 ms. The latest merged installation adds a 6.29-second sample with zero intervals over 33 ms. The report includes the callback counts and source revisions. Raw archives and personal data stay local.

Installed-source update, October 16

The cached year strip and the training-load card appear directly when materialized, matching the installed lazy dashboard. Cached dates, stable identities and scores keep their existing paths.

Review head: 3b09b85fd264. A local merge of the PRs reproduces the installed iPhone commit f88a1e12: 1,182 of 1,183 Apple product files are byte-identical; the remaining file uses the existing NoopMetrics.space3 token for the same 12-point spacing. The combined macOS build and iPhone Release build pass, including widgets and Watch components. The macOS run completes 2,352 app tests with three skipped and zero failures.

[AlexSchmidt1999]

I am using NOOP 12.1.0 Release build 456 on my iPhone 17 Pro Max, and the app runs very smoothly in everyday use.

This PR is included in that combined build, together with my other Apple changes and the performance fixes from #2724 by @UtkuDenizAltiok and #2705 by @kavemang. The installed source is d67cceb5.

Both Apple builds and the local app, analytics, database and Python test suites passed for this combined build.