Add EC consent logging and Sourcepoint consent support

[ChristianPavilonis]

Summary

• Adds EC consent decision logging so allow/block/withdrawal decisions are visible during request handling and finalization.
• Expands Sourcepoint consent mirroring to support multiple localStorage payload shapes for GPP and TCF consent.
• Adds Prebid User ID module build/config support.

Changes

File	Change
crates/trusted-server-core/src/consent/mod.rs	Adds explicit EC consent decision/reason modeling used by allows_ec_creation.
crates/trusted-server-core/src/ec/consent.rs	Surfaces EC consent decision details for EC lifecycle callers.
crates/trusted-server-core/src/ec/finalize.rs	Logs EC finalization actions, consent reasons, cookie/header state, and KV availability.
crates/trusted-server-core/src/ec/mod.rs	Tracks EC lifecycle state used by consent/finalization logging.
crates/trusted-server-core/src/integrations/registry.rs	Logs skipped EC generation decisions for non-navigation integration requests.
crates/trusted-server-core/src/publisher.rs	Logs skipped EC generation decisions for non-HTML publisher responses.
crates/trusted-server-adapter-fastly/src/logging.rs	Adjusts logging initialization/filtering for the new EC decision logs.
crates/js/lib/src/integrations/sourcepoint/index.ts	Mirrors Sourcepoint GPP/TCF consent from supported localStorage shapes into IAB cookies.
crates/js/lib/test/integrations/sourcepoint/index.test.ts	Adds Sourcepoint consent mirroring coverage.
crates/js/lib/build-all.mjs	Adds Prebid User ID module build support and liveIntent alias handling.
crates/js/lib/src/integrations/prebid/_user_id_modules.generated.ts	Adds generated Prebid User ID module import shim.
crates/js/lib/src/integrations/prebid/index.ts	Applies configured Prebid userSync settings.
crates/js/lib/test/integrations/prebid/index.test.ts	Adds Prebid User ID/userSync test coverage.
crates/trusted-server-core/src/integrations/prebid.rs	Adds user_sync config serialization into the injected Prebid JS config.
trusted-server.toml	Documents optional local Prebid User ID config.

Closes

Closes #

Test plan

• cargo test --workspace
• cargo clippy --workspace --all-targets --all-features -- -D warnings
• cargo fmt --all -- --check
• JS tests: cd crates/js/lib && npx vitest run
• JS format: cd crates/js/lib && npm run format
• Docs format: cd docs && npm run format
• WASM build: cargo build --package trusted-server-adapter-fastly --release --target wasm32-wasip1
• Manual testing via fastly compute serve
• Other: cargo fmt --all; cargo check --workspace; cd crates/js/lib && npx vitest run test/integrations/sourcepoint/index.test.ts test/integrations/prebid/index.test.ts

Checklist

• Changes follow CLAUDE.md conventions
• No unwrap() in production code — use expect("should ...")
• Uses tracing macros (not println!)
• New code has tests
• No secrets or credentials committed