refactor: DB-driven agent output events with single emission point

DB log chunk insertion is now the sole trigger for agent:output events.
Eliminates triple emission (FileTailer, handleStreamEvent, output buffer)
in favor of: FileTailer.onRawContent → DB insert → EventBus emit.

- createLogChunkCallback emits agent:output after successful DB insert
- spawnInternal now wires onRawContent callback (fixes session 1 gap)
- Remove eventBus from FileTailer (no longer touches EventBus)
- Remove eventBus from ProcessManager constructor (dead parameter)
- Remove agent:output emission from handleStreamEvent text_delta
- Remove outputBuffers map and all buffer helpers from manager/handler
- Remove getOutputBuffer from AgentManager interface and implementations
- getAgentOutput tRPC: DB-only, no file fallback
- onAgentOutput subscription: no initial buffer yield, events only
- AgentOutputViewer: accumulates raw JSONL chunks, parses uniformly

src/agent/manager.ts

@@ -59,7 +59,6 @@ export class MultiProviderAgentManager implements AgentManager {
   private static readonly MAX_COMMIT_RETRIES = 1;
 
   private activeAgents: Map<string, ActiveAgent> = new Map();
-  private outputBuffers: Map<string, string[]> = new Map();
   private commitRetryCount: Map<string, number> = new Map();
   private processManager: ProcessManager;
   private credentialHandler: CredentialHandler;
@@ -83,7 +82,7 @@ export class MultiProviderAgentManager implements AgentManager {
     private debug: boolean = false,
   ) {
     this.signalManager = new FileSystemSignalManager();
-    this.processManager = new ProcessManager(workspaceRoot, projectRepository, eventBus);
+    this.processManager = new ProcessManager(workspaceRoot, projectRepository);
     this.credentialHandler = new CredentialHandler(workspaceRoot, accountRepository, credentialManager);
     this.outputHandler = new OutputHandler(repository, eventBus, changeSetRepository, phaseRepository, taskRepository, pageRepository, this.signalManager);
     this.cleanupManager = new CleanupManager(workspaceRoot, repository, projectRepository, eventBus, debug, this.signalManager);
@@ -105,13 +104,12 @@ export class MultiProviderAgentManager implements AgentManager {
 
   /**
    * Centralized cleanup of all in-memory state for an agent.
-   * Cancels polling timer, removes from activeAgents, outputBuffers, and commitRetryCount.
+   * Cancels polling timer, removes from activeAgents and commitRetryCount.
    */
   private cleanupAgentState(agentId: string): void {
     const active = this.activeAgents.get(agentId);
     if (active?.cancelPoll) active.cancelPoll();
     this.activeAgents.delete(agentId);
-    this.outputBuffers.delete(agentId);
     this.commitRetryCount.delete(agentId);
   }
 
@@ -129,6 +127,15 @@ export class MultiProviderAgentManager implements AgentManager {
 
     return (content) => {
       repo.insertChunk({ agentId, agentName, sessionNumber, content })
+        .then(() => {
+          if (this.eventBus) {
+            this.eventBus.emit({
+              type: 'agent:output' as const,
+              timestamp: new Date(),
+              payload: { agentId, stream: 'stdout', data: content },
+            });
+          }
+        })
         .catch(err => log.warn({ agentId, err: err instanceof Error ? err.message : String(err) }, 'failed to persist log chunk'));
     };
   }
@@ -301,7 +308,8 @@ export class MultiProviderAgentManager implements AgentManager {
     // 6. Spawn detached subprocess
     const { pid, outputFilePath, tailer } = this.processManager.spawnDetached(
       agentId, alias, command, args, cwd ?? agentCwd, processEnv, providerName, prompt,
-      (event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId), this.outputBuffers),
+      (event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId)),
+      this.createLogChunkCallback(agentId, alias, 1),
     );
 
     await this.repository.update(agentId, { pid, outputFilePath });
@@ -452,7 +460,7 @@ export class MultiProviderAgentManager implements AgentManager {
 
     const { pid, outputFilePath, tailer } = this.processManager.spawnDetached(
       agentId, agent.name, command, args, agentCwd, processEnv, provider.name, commitPrompt,
-      (event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId), this.outputBuffers),
+      (event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId)),
       this.createLogChunkCallback(agentId, agent.name, commitSessionNumber),
     );
 
@@ -625,7 +633,7 @@ export class MultiProviderAgentManager implements AgentManager {
 
     const { pid, outputFilePath, tailer } = this.processManager.spawnDetached(
       agentId, agent.name, command, args, agentCwd, processEnv, provider.name, prompt,
-      (event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId), this.outputBuffers),
+      (event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId)),
       this.createLogChunkCallback(agentId, agent.name, resumeSessionNumber),
     );
 
@@ -666,13 +674,6 @@ export class MultiProviderAgentManager implements AgentManager {
     return this.outputHandler.getPendingQuestions(agentId, this.activeAgents.get(agentId));
   }
 
-  /**
-   * Get the buffered output for an agent.
-   */
-  getOutputBuffer(agentId: string): string[] {
-    return this.outputHandler.getOutputBufferCopy(this.outputBuffers, agentId);
-  }
-
   /**
    * Delete an agent and clean up all associated resources.
    */
@@ -759,7 +760,7 @@ export class MultiProviderAgentManager implements AgentManager {
     const reconcileLogChunkRepo = this.logChunkRepository;
     await this.cleanupManager.reconcileAfterRestart(
       this.activeAgents,
-      (agentId, event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId), this.outputBuffers),
+      (agentId, event) => this.outputHandler.handleStreamEvent(agentId, event, this.activeAgents.get(agentId)),
       (agentId, rawOutput, provider) => this.outputHandler.processAgentOutput(agentId, rawOutput, provider, (alias) => this.processManager.getAgentWorkdir(alias)),
       (agentId, pid) => {
         const { cancel } = this.processManager.pollForCompletion(