Port Telemetry, Format, RideStatistics; add cross-language parity harness

T03 — telemetry.dart, format.dart, live_telemetry.dart, plus pure domain models
(Trip/Segment/TrackPoint/RideStats) with no persistence dependency, so Drift can
map to them in T08 rather than the domain depending on the database.

T04 — ride_statistics.dart including ElevationAccumulator, ported structurally
faithfully: moving average, reversal hysteresis, gainIncludingPending, and the
finish() reconciliation against lastRaw.

T07 (early, because T04 forced it) — tool/parity/ drives identical fixtures
through the real Kotlin files and the Dart port, then diffs. Result: every value
byte-identical, including noisy_gain=38.959594555022136 to the last digit. The
sole difference is run_avg_speed, where Kotlin's 32-bit Float widens to double
with artefacts Dart's binary64 does not reproduce. Documented, not papered over.

That harness settled a real question. The ported elevation test failed at 50.9m
against Kotlin's 35m bound, which looked like a porting bug. It was not: Kotlin's
and Dart's Random(42) are different streams. On a shared LCG fixture both produce
39.0m -- which would also fail Kotlin's own bound. The native guard passes on seed
luck rather than on a property of the algorithm. The Dart test now uses the shared
LCG, asserts bit-equality with Kotlin, and sets its bound from measured behaviour
(25 seeds spanned 24.7-46.7m).

52 tests passing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

pubspec.lock

@@ -472,7 +472,7 @@ packages:
     source: sdk
     version: "0.0.0"
   intl:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: intl
       sha256: "1ca20c894b1717686a2319b8548763d812bc0aabdac580420a44c5178c57a867"