Add PHP Analyzer Plugin and Composer Lock Data Handling

- Implemented the PhpAnalyzerPlugin to analyze PHP projects.
- Created ComposerLockData class to represent data from composer.lock files.
- Developed ComposerLockReader to load and parse composer.lock files asynchronously.
- Introduced ComposerPackage class to encapsulate package details.
- Added PhpPackage class to represent PHP packages with metadata and evidence.
- Implemented PhpPackageCollector to gather packages from ComposerLockData.
- Created PhpLanguageAnalyzer to perform analysis and emit results.
- Added capability signals for known PHP frameworks and CMS.
- Developed unit tests for the PHP language analyzer and its components.
- Included sample composer.lock and expected output for testing.
- Updated project files for the new PHP analyzer library and tests.

docs/modules/graph/architecture.md

@@ -19,7 +19,8 @@
 1. **Ingestion:** Cartographer/SBOM Service emit SBOM snapshots (`sbom_snapshot` events) captured by the Graph Indexer. Advisories/VEX from Concelier/Excititor generate edge updates, policy runs attach overlay metadata.
 2. **ETL:** Normalises nodes/edges into canonical IDs, deduplicates, enforces tenant partitions, and writes to the graph store (planned: Neo4j-compatible or document + adjacency lists in Mongo).
 3. **Overlay computation:** Batch workers build materialised views for frequently used queries (impact lists, saved queries, policy overlays) and store as immutable blobs for Offline Kit exports.
-4. **Diffing:** `graph_diff` jobs compare two snapshots (e.g., pre/post deploy) and generate signed diff manifests for UI/CLI consumption.
+4. **Diffing:** `graph_diff` jobs compare two snapshots (e.g., pre/post deploy) and generate signed diff manifests for UI/CLI consumption.
+5. **Analytics (Runtime & Signals 140.A):** background workers run Louvain-style clustering + degree/betweenness approximations on ingested graphs, emitting overlays per tenant/snapshot and writing cluster ids back to nodes when enabled.
 
 ## 3) APIs
 
@@ -44,7 +45,8 @@
 
 ## 6) Observability
 
-- Metrics: ingestion lag (`graph_ingest_lag_seconds`), node/edge counts, query latency per saved query, overlay generation duration.
+- Metrics: ingestion lag (`graph_ingest_lag_seconds`), node/edge counts, query latency per saved query, overlay generation duration.
+- New analytics metrics: `graph_analytics_runs_total`, `graph_analytics_failures_total`, `graph_analytics_clusters_total`, `graph_analytics_centrality_total`, plus change-stream/backfill counters (`graph_changes_total`, `graph_backfill_total`, `graph_change_failures_total`, `graph_change_lag_seconds`).
 - Logs: structured events for ETL stages and query execution (with trace IDs).
 - Traces: ETL pipeline spans, query engine spans.