fix(cache): invalidate framework dependencies when equal-size file lists change

[nk33-dev]

Problem

Framework dependency detection caches its answer by the number of indexed files. Replacing one source tree with another of the same size can retain the old dependencies. The resolver also repeatedly materializes the same tracked-file list while the database is unchanged.

Changes

• Memoize the sorted file list using the existing database change stamp (local writes and commits through other connections).
• Freeze the cached array and expose it as readonly.
• Do not reuse a memo inside a transaction; clear it on connection rebind.
• Key dependency detection by the file-list identity instead of its length.

This is limited to file lists and framework dependencies. It does not modify the node-name or stats caches proposed in #2115.

Validation

Windows, upstream baseline 7ba8eee.

• npx tsc --noEmit passed.
• 12 focused tests passed: seven file-list lifecycle tests, four existing monorepo framework tests, and one equal-size dependency replacement regression.
• Coverage includes same-connection writes, another connection's commit, rollback, rebind, and caller mutation.
• git diff --check passed.

No indexing-time or memory benchmark has been run, so this PR does not claim a measured speedup. Full-suite and cross-platform validation are left to CI.