Implement declaration-granular incremental compilation and reusable state

Parent: #8
Blocked by: #34, #38, and #40

Outcome

Implement Warm Compilation through the persistent NativeAOT service, declaration-aware semantic queries, and versioned memory and content-addressed disk caches.

Acceptance criteria

• Query keys include complete source, reference, option, toolchain, schema, and artifact-affecting inputs.
• Explicit declaration dependencies and file checkpoints drive reuse and conservative invalidation; the final link remains fresh.
• Exported, implementation, debug, and diagnostic fingerprints explain every reuse, recheck, re-lower, and re-emit decision.
• Standalone clean compilation is the correctness reference for every reused result.
• Service ownership, epochs, concurrency, cancellation, protocol negotiation, stale-daemon recovery, compare-and-swap state publication, isolation, integrity, eviction, and restart reuse are defined and tested.
• Failed requests do not advance last-successful state or artifacts; uncertainty widens invalidation.
• Cold Compilation bypasses both cache levels, cache layout stays private, and structured evidence satisfies #19 without treating MSBuild skips as Warm Compilation.

Decision inputs

Issues #12 and #19; ADRs 0003, 0013, 0016, 0018, and 0022.

This issue inherits the corpus-neutral acceptance policy in #8.

Start with parent issue #8, blockers #34, #38, and #40, then read ADRs 0003, 0013, 0016, 0018, and 0022 alongside the persistent NativeAOT service, semantic-query, cache, and compilation requirements. No files or tests are named; done means the listed acceptance criteria are defined and tested, with clean compilation remaining the correctness reference.