fix: update tantivy 0.22→0.25, scraper 0.22→0.25, quinn-proto→0.11.14

Resolves cargo audit failures:
- RUSTSEC-2024-0384 (instant, unmaintained) — removed by tantivy upgrade
- RUSTSEC-2026-0037 (quinn-proto, DoS) — fixed by cargo update
- scraper advisory — resolved by version bump

Remaining warning: lru 0.12.5 (RUSTSEC-2026-0002) pinned by tantivy,
not a blocking error.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

compliance-graph/Cargo.toml

@@ -28,7 +28,7 @@ tree-sitter-typescript = "0.23"
 petgraph = "0.7"
 
 # Text search
-tantivy = "0.22"
+tantivy = "0.25"
 
 # Serialization
 bson = { version = "2", features = ["chrono-0_4"] }