feat(snapshot): export-snapshot + import-snapshot — share CodeLens graph across team (closes #12)

[Wolfvin]

Summary

Implements issue #12: team graph snapshot export/import.

Commands

• codelens export-snapshot [--output path] — export graph as .gz
• codelens import-snapshot [--input path] [--merge] — restore graph

Files

• New: scripts/commands/export_snapshot.py
• New: scripts/commands/import_snapshot.py
• New: scripts/snapshot_io.py (shared snapshot format helpers)
• New: tests/test_snapshot.py (15 round-trip + merge + validation tests)
• Synced: docs/metadata command counts (63 → 65) via sync_command_count.py

Verification

• Tests: 802 passed, 87 skipped, 1 pre-existing unrelated failure (test_hybrid_engine query confidence — environment-dependent, failing on baseline before this PR)
• Round-trip: export → import → query = same results (graph-schema matches; all 5 tables match row-for-row)
• Snapshot size on smoke fixture: 592 B (gzip-compressed JSON)
• Constraint honored: snapshot contains graph metadata only — no file content (files table stores content_hash, not bytes)

Closes #12

[chatgpt-codex-connector]

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[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud