Bump to 9.2.2 (versionCode 305) so a testing build can install over 9.2.2/304

[ryanbr]

Version bump only, no code.

Why now

The testing build cut from main an hour ago compiled green on all three platforms — but would not install on a phone carrying the 29 July staging build:

	versionName	versionCode
installed (29 Jul staging)	9.2.2	304
testing build from main	9.2.1	303

Android refuses a lower versionCode over a higher one and reports it as "App not installed", which names neither the cause nor the file. main has sat on 9.2.1 for 42 commits; the bump was simply overdue and this is what made it visible.

versionCode goes to 305, not 304, because 304 is already published on the rolling testing-latest tag — reusing it would leave two different builds sharing a code.

MARKETING_VERSION and versionName move together, per CLAUDE.md.

Not in this PR

Release notes. 9.2.2 still owes users the visible changes from those 42 commits, and they are not cosmetic:

• Effort shifts twice — Strain: weight each HR sample by its own gap, not the window's first one #963 (per-sample HR gap weighting) and Workouts: score the SAVED workout with the measured resting HR (#983) #992 (saved workouts now use measured resting HR). Both can move a number in either direction, and Strain: weight each HR sample by its own gap, not the window's first one #963 applies retroactively on recompute.
• A new Apple Health permission prompt — existing iOS users will be asked for Water and Caffeine on their next foreground sync (Hydration: import water from Apple Health and Health Connect (#949) #974/Caffeine: import intakes from Apple Health (#949) #985).
• Oura resting-HR heal — fix(import): select Oura's main sleep session for the daily rollup #375 fixes days where a nap fragment beat the real night, producing 90+ bpm resting-HR spikes. Affected users must re-sync to heal already-imported days, and will not know to unless the notes say so.
• Sleep staging changes — Sleep: forbid wake → deep/REM transitions — the one part of #348 that survives a de-contaminated benchmark #987 forbids wake → deep/REM. Stored hypnograms are untouched, so timelines mix recipes across the change.

That is a notes-writing job rather than a bump, so it is deliberately separate.