refactor(ingestion): drop dead legacy execution-ingestion path

ExecutionController was @ConditionalOnMissingBean(ChunkAccumulator.class),
and ChunkAccumulator is registered unconditionally — the legacy controller
never bound in any profile. Even if it had, IngestionService.ingestExecution
called executionStore.upsert(), and the only ExecutionStore impl
(ClickHouseExecutionStore) threw UnsupportedOperationException from upsert
and upsertProcessors. The entire RouteExecution → upsert path was dead code
carrying four transitive dependencies (RouteExecution import, eventPublisher
wiring, body-size-limit config, searchIndexer::onExecutionUpdated hook).

Removed:
- cameleer-server-app/.../controller/ExecutionController.java (whole file)
- ExecutionStore.upsert + upsertProcessors (interface methods)
- ClickHouseExecutionStore.upsert + upsertProcessors (thrower overrides)
- IngestionService.ingestExecution + toExecutionRecord + flattenProcessors
  + hasAnyTraceData + truncateBody + toJson/toJsonObject helpers
- IngestionService constructor now takes (DiagramStore, WriteBuffer<Metrics>);
  dropped ExecutionStore + Consumer<ExecutionUpdatedEvent> + bodySizeLimit
- StorageBeanConfig.ingestionService(...) simplified accordingly

Untouched because still in use:
- ExecutionRecord / ProcessorRecord records (findById / findProcessors /
  SearchIndexer / DetailController)
- SearchIndexer (its onExecutionUpdated never fires now since no-one
  publishes ExecutionUpdatedEvent, but SearchIndexerStats is still
  referenced by ClickHouseAdminController — separate cleanup)
- TaggedExecution record has no remaining callers after this change —
  flagged in core-classes.md as a leftover; separate cleanup.

Rule docs updated:
- .claude/rules/app-classes.md: retired ExecutionController bullet, fixed
  stale URL for ChunkIngestionController (it owns /api/v1/data/executions,
  not /api/v1/ingestion/chunk/executions).
- .claude/rules/core-classes.md: IngestionService surface + note the dead
  TaggedExecution.

Full IT suite post-removal: 560 tests run, 11 F + 1 E — same 12 failures
in the same 3 previously-parked classes (AgentSseControllerIT / SseSigningIT
SSE-timing + ClickHouseStatsStoreIT timezone bug). No regression.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude/rules/core-classes.md

@@ -107,8 +107,8 @@ paths:
 
 ## ingestion/ — Buffered data pipeline
 
-- `IngestionService` — ingestExecution, ingestMetric, ingestLog, ingestDiagram
-- `ChunkAccumulator` — batches data for efficient flush
+- `IngestionService` — diagram + metrics facade (`ingestDiagram`, `acceptMetrics`, `getMetricsBuffer`). Execution ingestion went through here via the legacy `RouteExecution` shape until `ChunkAccumulator` took over writes from the chunked pipeline — the `ingestExecution` path plus its `ExecutionStore.upsert` / `upsertProcessors` dependencies were removed.
+- `ChunkAccumulator` — batches data for efficient flush; owns the execution write path (chunks → buffers → flush scheduler → `ClickHouseExecutionStore.insertExecutionBatch`).
 - `WriteBuffer` — bounded ring buffer for async flush
 - `BufferedLogEntry` — log entry wrapper with metadata
-- `MergedExecution`, `TaggedExecution`, `TaggedDiagram` — tagged ingestion records. `TaggedDiagram` carries `(instanceId, applicationId, environment, graph)` — env is resolved from the agent registry in the controller and stamped on the ClickHouse `route_diagrams` row.
+- `MergedExecution`, `TaggedDiagram` — tagged ingestion records. `TaggedDiagram` carries `(instanceId, applicationId, environment, graph)` — env is resolved from the agent registry in the controller and stamped on the ClickHouse `route_diagrams` row. (`TaggedExecution` still lives in the package as a leftover but has no callers since the legacy PG ingest path was retired.)