fix: align server with protocol v2 chunked transport spec

- ChunkIngestionController: /data/chunks → /data/executions (matches
  PROTOCOL.md endpoint the agent actually posts to)
- ExecutionController: conditional on ClickHouse being disabled to
  avoid mapping conflict
- Persist originalExchangeId and replayExchangeId from ExecutionChunk
  envelope through to ClickHouse (was silently dropped)
- V5 migration adds the two new columns to executions table

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/test/java/com/cameleer3/server/app/search/ClickHouseSearchIndexIT.java

@@ -71,7 +71,8 @@ class ClickHouseSearchIndexIT {
                 "hash-abc", "FULL",
                 "{\"order\":\"12345\"}", "", "", "", "{\"env\":\"prod\"}",
                 "", "",
-                false, false
+                false, false,
+                null, null
         );
 
         // exec-2: FAILED, route-timer, agent-a, my-app, corr-2, 200ms, with error
@@ -87,7 +88,8 @@ class ClickHouseSearchIndexIT {
                 "", "FULL",
                 "", "", "", "", "",
                 "", "",
-                false, false
+                false, false,
+                null, null
         );
 
         // exec-3: COMPLETED, route-rest, agent-b, other-app, 100ms, no error
@@ -101,7 +103,8 @@ class ClickHouseSearchIndexIT {
                 "", "FULL",
                 "", "", "", "", "",
                 "", "",
-                false, false
+                false, false,
+                null, null
         );
 
         store.insertExecutionBatch(List.of(exec1, exec2, exec3));

cameleer3-server-app/src/test/java/com/cameleer3/server/app/storage/ClickHouseExecutionStoreIT.java

@@ -68,7 +68,8 @@ class ClickHouseExecutionStoreIT {
                 "{\"h1\":\"v1\"}", "{\"h2\":\"v2\"}",
                 "{\"attr\":\"val\"}",
                 "trace-123", "span-456",
-                true, false
+                true, false,
+                null, null
         );
 
         store.insertExecutionBatch(List.of(exec));
@@ -195,7 +196,8 @@ class ClickHouseExecutionStoreIT {
                 "", "FULL",
                 "", "", "", "", "",
                 "", "",
-                false, false
+                false, false,
+                null, null
         );
 
         MergedExecution v2 = new MergedExecution(
@@ -208,7 +210,8 @@ class ClickHouseExecutionStoreIT {
                 "", "FULL",
                 "", "", "", "", "",
                 "", "",
-                false, false
+                false, false,
+                null, null
         );
 
         store.insertExecutionBatch(List.of(v1));