[codex] Bump Temper authz candidate index

[rita-aga]

Summary

• Bumps TemperPaw's Temper dependencies to 84e95c6677f4a03364dea796cc67237bbc8275ce, which contains the AuthZ candidate-selection index from Temper PR Paw Patrol WorkerRun en-019e0614-2cb5-7b33-84cf-b5f40b7f48e1 #240.
• Keeps the production observability contract coherent by updating the Docker TEMPER_OBSERVABILITY_REV, Datadog contract expected revisions, WASM SDK manifests, and stale WASM lockfile git sources.
• Preserves the prior version-pin discipline so host/runtime, guest WASM modules, and observability proof paths all resolve to the same Temper revision.

Why

The live AuthZ candidate-filter proof showed that Cedar evaluator work dropped from 16,497 policies to 48 candidates, but phase:policy_candidates still cost about 13.4 ms p95. Temper PR #240 moves that candidate selection to a precomputed per-policy-set index without decision caching or Cedar bypass. This PR rolls that Temper change into TemperPaw so it can be deployed and verified in production Datadog.

Validation

• cargo check -p temperpaw --locked
• cargo test -p temperpaw --test datadog_observability_contract (31 tests)
• cargo fmt --all -- --check
• git diff --check
• rg confirmed the previous Temper rev is absent from the rollout tree