chore: Mark US-008 as complete, update progress log

Author: LoCoBench Bot

ralph-gapfill-docgen/prd.json

@@ -99,7 +99,7 @@
       ],
       "priority": 7,
       "passes": true,
-      "notes": "Terraform v1.9.0 → v1.10.0 (commits 7637a92 → 24236f4). Breaking changes: S3 backend assume_role migration, moved blocks resource. prefix, sensitive value conditionals, ephemeral resources. Registered in selected_benchmark_tasks.json (mcp_benefit_score=0.887) and docgen_2config.sh."
+      "notes": "Terraform v1.9.0 \u2192 v1.10.0 (commits 7637a92 \u2192 24236f4). Breaking changes: S3 backend assume_role migration, moved blocks resource. prefix, sensitive value conditionals, ephemeral resources. Registered in selected_benchmark_tasks.json (mcp_benefit_score=0.887) and docgen_2config.sh."
     },
     {
       "id": "US-008",
@@ -112,8 +112,8 @@
         "Task registered"
       ],
       "priority": 8,
-      "passes": false,
-      "notes": "Envoy xDS v2\u2192v3 migration is well-documented. Choose a narrower scope \u2014 e.g., changes in a specific filter's config proto between two versions."
+      "passes": true,
+      "notes": "Envoy v1.30.0 \u2192 v1.31.0 (commits 50ea83e \u2192 7b8baff). Focus on ext_proc filter: observability mode deprecates async_mode, new grpc_initial_metadata/metadata_options/request_attributes/response_attributes fields, upstream filter support, HTTP/2 codec change. Registered in selected_benchmark_tasks.json (mcp_benefit_score=0.880) and docgen_2config.sh."
     }
   ]
 }

ralph-gapfill-docgen/progress.txt

@@ -173,3 +173,27 @@
   - Pass threshold for all docgen tasks: 0.7 overall score
   - Ground truth covers 4 major Terraform v1.10 changes: S3 backend IAM role deprecation + native state locking, moved blocks syntax, sensitive marks in conditionals, ephemeral resources/values
 ---
+## 2026-02-16 - US-008
+- Created docgen-migration-002: Envoy External Processing (ext_proc) Filter Migration Guide (v1.30 → v1.31)
+- Files created:
+  - benchmarks/ccb_docgen/docgen-migration-002/task.toml (category=migration_guide, language=cpp, difficulty=hard, time_limit_sec=1200)
+  - benchmarks/ccb_docgen/docgen-migration-002/instruction.md (covers ext_proc filter: observability mode, new config fields, upstream filter support)
+  - benchmarks/ccb_docgen/docgen-migration-002/tests/ground_truth.json (4 scoring categories: breaking_changes, migration_steps, code_examples, documentation_structure)
+  - benchmarks/ccb_docgen/docgen-migration-002/tests/test.sh (copied from docgen-migration-001, generic Python-based verifier)
+  - benchmarks/ccb_docgen/docgen-migration-002/environment/Dockerfile (git worktrees for v1.30.0 and v1.31.0)
+- Files modified:
+  - configs/docgen_2config.sh (added docgen-migration-002 to ALL_TASK_IDS and TASK_SG_REPO_NAMES)
+  - configs/selected_benchmark_tasks.json (registered task with mcp_benefit_score=0.880, total_selected: 197→198)
+- **Learnings for future iterations:**
+  - Envoy v1.30.0 → v1.31.0 focus: ext_proc filter configuration changes (narrower scope than full xDS v2→v3 migration)
+  - Used WebSearch and WebFetch to research Envoy release notes from official docs (v1.30.0 April 2024, v1.31.0 July 2024)
+  - Found specific commits via WebFetch from GitHub releases: v1.30.0 (50ea83e602), v1.31.0 (7b8baff175)
+  - Key breaking changes: observability_mode deprecates async_mode, HTTP/2 codec default change (oghttp2 → true), upstream filter chain support
+  - Ground truth covers 5 breaking changes (observability mode, HTTP/2 codec, ProcessingMode, upstream filters, new config fields), 5 migration steps, 4 code examples
+  - Same 4-category scoring as docgen-migration-001: breaking_changes (0.50), migration_steps (0.30), code_examples (0.15), documentation_structure (0.05)
+  - MCP benefit score (0.880) reflects high cross_file_deps (0.93) and semantic_search_potential (0.94) for finding API changes across proto/impl
+  - Weight validation critical: verified all category weights sum to 1.0 and top-level weights sum to 1.0
+  - Dockerfile pattern matches docgen-migration-001: git worktrees for two versions, remove main clone to save space
+  - Ext_proc filter spans: api/envoy/extensions/filters/http/ext_proc/v3/ (proto), source/extensions/filters/http/ext_proc/ (impl), docs/root/configuration/http/http_filters/ext_proc_filter.rst (docs)
+  - Migration tasks benefit most from MCP (task_category_weight=0.75) compared to API reference (0.70) and architecture (0.65)
+---