feat: YAML pipeline template autocomplete (AzDO + GHA)

- Add scripts/sync_pipeline_templates.py — scans LRU AzDO and GHA template
  repos; outputs unified pipeline_templates_catalog.json (48 templates: 45
  AzDO + 3 GHA)
- Add scripts/template_sources.yml — source config (AzDO alias, GHA org)
- Add pipeline_templates_catalog.json — baked catalog (49 KB)
- Add ilsp/yaml_lsp/catalog.py — PipelineTemplateCatalog with completion item
  generators for template paths, param names, allowed values, GHA inputs
- Add ilsp/yaml_lsp/proxy.py — async WS↔TCP bridge with LSP frame buffering,
  per-connection document tracking, AzDO/GHA context detection, and completion
  injection (LRU items sortText 0_, standard items downgraded to 9_)
- Wire yaml_ws_handler into server.py (replaces raw _ws_proxy call)
- Load PipelineTemplateCatalog at startup; reload + health report template count
- Update push_catalogs.sh to push pipeline_templates_catalog.json
- Update Dockerfile to bake pipeline_templates_catalog.json as image fallback
- Add tests/test_yaml_catalog.py (14 tests) + tests/test_yaml_proxy.py (18 tests)
  All 67 tests green

scripts/template_sources.yml

@@ -0,0 +1,26 @@
+# Pipeline template sources for YAML autocomplete
+# Consumed by scripts/sync_pipeline_templates.py
+
+sources:
+
+  # AzDO template repos — referenced via @alias in pipeline YAML
+  azdo:
+    - alias: pipeline-templates
+      local_path: ~/IdeaProjects/Bitbucket/Drift/pipeline-templates
+      # Relative subpaths to scan (empty = entire repo)
+      scan_dirs:
+        - tasks
+        - stages
+        - jobs
+        - variables
+      # File extensions to scan
+      extensions: [.yaml, .yml]
+
+  # GitHub Actions reusable workflows — referenced via uses: org/repo/.github/workflows/file@ref
+  gha:
+    - org: LRU-Digital
+      local_base: ~/IdeaProjects/GitHub/LRU-Digital
+      # Only scan repos that have reusable workflows (workflow_call trigger)
+      # Leave empty to scan all repos under local_base
+      repos: []
+      default_ref: main