Add missing activity types for pull_request and pull_request_target (#242)

Fixes #51

Added the following activity types to pull_request and pull_request_target:
- milestoned
- demilestoned
- enqueued
- dequeued

These types were missing from workflow-v1.0.json but are valid workflow
triggers per GitHub docs.

Also added schema-sync.test.ts to ensure activity types in workflow-v1.0.json
stay in sync with webhooks.json. The test:
- Checks both directions (webhooks→schema and schema→webhooks)
- Has WEBHOOK_ONLY for types not valid as workflow triggers:
  - check_suite: requested, rerequested
  - registry_package: default
- Has SCHEMA_ONLY for types valid in workflows but not in webhooks:
  - registry_package: updated
- Has NAME_MAPPINGS for naming differences:
  - project_column: edited (webhook) ↔ updated (schema)
- Provides actionable error messages when mismatches are found

workflow-parser/src/workflow-v1.0.json

@@ -856,7 +856,7 @@
       }
     },
     "pull-request-activity": {
-      "description": "The types of pull request activity that trigger the workflow. Supported activity types: `assigned`, `unassigned`, `labeled`, `unlabeled`, `opened`, `edited`, `closed`, `reopened`, `synchronize`, `converted_to_draft`, `ready_for_review`, `locked`, `unlocked`, `review_requested`, `review_request_removed`, `auto_merge_enabled`, `auto_merge_disabled`.",
+      "description": "The types of pull request activity that trigger the workflow. Supported activity types: `assigned`, `unassigned`, `labeled`, `unlabeled`, `opened`, `edited`, `closed`, `reopened`, `synchronize`, `converted_to_draft`, `locked`, `unlocked`, `enqueued`, `dequeued`, `milestoned`, `demilestoned`, `ready_for_review`, `review_requested`, `review_request_removed`, `auto_merge_enabled`, `auto_merge_disabled`.",
       "one-of": [
         "pull-request-activity-type",
         "pull-request-activity-types"
@@ -879,9 +879,13 @@
         "reopened",
         "synchronize",
         "converted_to_draft",
-        "ready_for_review",
         "locked",
         "unlocked",
+        "enqueued",
+        "dequeued",
+        "milestoned",
+        "demilestoned",
+        "ready_for_review",
         "review_requested",
         "review_request_removed",
         "auto_merge_enabled",
@@ -1004,7 +1008,7 @@
       }
     },
     "pull-request-target-activity": {
-      "description": "The types of pull request activity that trigger the workflow. Supported activity types: `assigned`, `unassigned`, `labeled`, `unlabeled`, `opened`, `edited`, `closed`, `reopened`, `synchronize`, `converted_to_draft`, `ready_for_review`, `locked`, `unlocked`, `review_requested`, `review_request_removed`, `auto_merge_enabled`, `auto_merge_disabled`.",
+      "description": "The types of pull request activity that trigger the workflow. Supported activity types: `assigned`, `unassigned`, `labeled`, `unlabeled`, `opened`, `edited`, `closed`, `reopened`, `synchronize`, `converted_to_draft`, `locked`, `unlocked`, `enqueued`, `dequeued`, `milestoned`, `demilestoned`, `ready_for_review`, `review_requested`, `review_request_removed`, `auto_merge_enabled`, `auto_merge_disabled`.",
       "one-of": [
         "pull-request-target-activity-type",
         "pull-request-target-activity-types"
@@ -1027,9 +1031,13 @@
         "reopened",
         "synchronize",
         "converted_to_draft",
-        "ready_for_review",
         "locked",
         "unlocked",
+        "enqueued",
+        "dequeued",
+        "milestoned",
+        "demilestoned",
+        "ready_for_review",
         "review_requested",
         "review_request_removed",
         "auto_merge_enabled",