docs(15-03): complete log aggregator sources plan

- Elasticsearch, Grafana, Sentry, Kibana, Splunk sources implemented
- 5 sources + 5 test files, all passing
- Requirements RECON-LOG-01, RECON-LOG-02, RECON-LOG-03 complete

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
 status: executing
-stopped_at: Completed 15-01-PLAN.md
-last_updated: "2026-04-06T13:30:40.402Z"
+stopped_at: Completed 15-03-PLAN.md
+last_updated: "2026-04-06T13:32:52.614Z"
 last_activity: 2026-04-06
 progress:
   total_phases: 18
   completed_phases: 14
   total_plans: 81
-  completed_plans: 79
+  completed_plans: 80
   percent: 20
 ---
 
@@ -98,6 +98,7 @@ Progress: [██░░░░░░░░] 20%
 | Phase 13 P04 | 5min | 2 tasks | 3 files |
 | Phase 14 P01 | 4min | 1 tasks | 14 files |
 | Phase 15 P01 | 3min | 2 tasks | 13 files |
+| Phase 15 P03 | 4min | 2 tasks | 11 files |
 
 ## Accumulated Context
 
@@ -146,6 +147,7 @@ Recent decisions affecting current work:
 - [Phase 13]: RegisterAll extended to 40 sources (28 Phase 10-12 + 12 Phase 13); package registry sources credentialless, no new SourcesConfig fields
 - [Phase 14]: RegisterAll extended to 45 sources (40 Phase 10-13 + 5 Phase 14 CI/CD); CircleCI gets dedicated CIRCLECI_TOKEN
 - [Phase 15]: Discord/Slack use dorking approach (configurable search endpoint) since neither has public message search API
+- [Phase 15]: Log aggregator sources are credentialless, targeting exposed instances
 
 ### Pending Todos
 
@@ -160,6 +162,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-04-06T13:30:40.398Z
-Stopped at: Completed 15-01-PLAN.md
+Last session: 2026-04-06T13:32:52.610Z
+Stopped at: Completed 15-03-PLAN.md
 Resume file: None