fix: reload on route manifest metadata changes

[ScriptedAlchemy]

Summary

• detect dev route manifest metadata changes such as loader/clientLoader/export flag changes
• trigger a full browser reload for those changes instead of relying on a React Router Vite-only route HMR runtime
• add runtime and controller tests proving the reload path

Validation

• pnpm test:core
• pnpm build
• git diff --check

Notes

Stacked on codex/asset-query-parity. This intentionally chooses the conservative full-reload fallback because the Rsbuild plugin does not currently ship React Router's Vite route-HMR runtime.

[github-actions]

Benchmark Results

Compared PR head 6ab91d0 against base 8b08bd7.

Total median wall time: 11.89s -> 11.96s (+0.6%, 0.99x speedup)
Compiler ready median: 9.82s -> 9.81s (-0.1%)
Route load median: 2.03s -> 2.11s (+4.0%)

Benchmark	Base total	Head total	Delta	Head ready	Head routes	Speedup	Head RSS p95
large-355-ssr-esm	11.89s	11.96s	+0.6%	9.81s	2.11s	0.99x	-

Profile: large; mode: dev; iterations: 3; warmup: 0.
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