Apply deps filters before graph materialization

[Widthdom]

Summary

• Push deps exact-symbol, symbol-family, and noise filters into SQLite before graph materialization, ranking, and display limits.
• Preserve cycle, workspace, cross-database, path-derived, and degraded-output contracts while making long dependency reads cancellable.
• Bound combined --symbol / --symbol-family input cardinality before opening SQLite.
• Add repository-scale, filter-ordering, compatibility, degradation, cancellation, and boundary regression coverage.

Root cause

RunDeps materialized and ranked broad dependency candidates before applying symbol and noise filters. Consequently, --limit 1 still processed the repository-wide graph, and SQL pushdown also needed explicit safeguards for SQLite expression depth.

Validation

• Reproduction query (deps --symbol TryReadUtf8File --limit 1 --json --no-progress): completed in 2.27 seconds (Issue report: 10m37s).
• Release full suite on the core implementation:
  • net8.0: 9,716 passed, 6 skipped, 0 failed.
  • net9.0: 9,250 passed, 411 skipped, 0 failed.
• Final Release dependency-focused suite after review fixes:
  • net8.0: 91 passed, 0 failed.
  • net9.0: 90 passed, 1 skipped, 0 failed.
• Debug and Release solution builds: 0 warnings, 0 errors.
• dotnet format CodeIndex.sln --verify-no-changes --no-restore.
• Changelog fragment validation: 80 fragments.

Adversarial review

• Round 1: three actionable findings; all fixed and regression-tested.
• Round 2: one actionable filter-cardinality finding; fixed with accepted-maximum and maximum-plus-one tests.
• The repository workflow maximum of two rounds is complete.

Documentation and changelog

• Updated the English and Japanese dependency-query documentation in their respective sections.
• Added changelog.d/unreleased/4619.fixed.md.

Follow-up candidates

• None.

Fixes #4619