Fix: harden renderer recovery invariants and input handling

[ael-dev3]

Summary

Stacked follow-up to #80 for the main ael-dev3/Warpkeep repository. This PR keeps the renderer recovery scope focused and removes the remaining lifecycle/input gaps without duplicating the recovery implementation already in #80.

Base / head

• Base: fix/realm-renderer-recovery @ fb5ded3e44f27c867fa9a092edce261bb4079f6a (PR Fix: recover the Realm renderer without entering the full-world fallback #80)
• Head: fix/realm-renderer-recovery-followup @ dc9ac4066cb4427dce733713e01789532fb661e3
• Target repository: ael-dev3/Warpkeep
• PR docs: restore Realm preview in README #79 is untouched.

Changes

• Make WebGL2 the authoritative, cached capability probe; WebGL1 cannot enter the Realm renderer path.
• Enforce the lifecycle invariant that a renderer which has presented a frame can never fall back to static compatibility mode.
• Add monotonic renderer-generation telemetry and explicit failure-code/context-loss/context-restore DOM counters.
• Suspend pointer, wheel, label-click, and camera gesture input synchronously during WebGL context loss; cancel active gestures and pause ambience.
• Record bounded context loss/restore telemetry and resume/rebuild through the existing attestation-preserving recovery path.
• Add a deterministic short yield before the single allowed Compact castle transport retry.
• Remove the retired exact fallback sentence from the compatibility surface and use precise recovery-safe copy.
• Extend lifecycle, context-event, fallback-copy, and cleanup regression coverage.
• Document the follow-up recovery invariants and diagnostics.

Verification

• tsc -b
• vitest run: 197 files, 1,756 tests passed
• vitest run tests/realmRendererRecovery.test.ts tests/realmSceneCleanup.test.ts tests/realmMapScreen.test.tsx tests/realmQualityRecreation.test.tsx: 4 files, 78 tests passed
• vite build
• git diff --check

Non-goals / safety

No backend, SpacetimeDB, authorization, asset, Water Engine, DNS, Pages, or production deployment changes are included. Durable world state remains outside the renderer lifecycle.

[ael-dev3]

Superseded by #95, which carries the renderer invariants and follow-up fixes in the released Alpha 0.3.14 tree.