feat(backends): multi-backend intelligence layer — LLM + Agent backends, persona-loading agents, honest CLI commands

Add IntelligenceBackend abstraction with two categories:
- LLMBackend (OllamaLocal, OllamaCloud): CI runs tool loop, provides tools, constructs prompts
- AgentBackend (Opencode): agent runs own tool loop, CI serializes request

Refactor all 18 agents from hardcoded stubs to persona loaders that delegate
to the active backend or fail honestly when no backend is available.

Refactor OrchestratorAgent.executeStage() from monolithic switch to agent
delegation via STAGE_AGENT_MAP for intelligent stages (research, plan, execute,
verify), with mechanical stages (specify, clarify, complete) staying inline.

Wire CLI commands with --backend flag and auto-detection (opencode →
ollama-local → ollama-cloud). Harden rollback/ship with real git operations.
No command returns fake success.

src/agents/orchestrator.ts

@@ -6,7 +6,7 @@ import { GitContext, ProjectState } from "../core/git-context.js";
 import { GitBranch } from "../core/git-branch.js";
 import { CiFiles } from "../core/ci-files.js";
 import { CommitBuilder } from "../core/commit-builder.js";
-import { CIConfig } from "../types/config.js";
+import { CIConfig, AgentName } from "../types/config.js";
 import {
   PipelineState,
   PipelineStage,
@@ -17,6 +17,8 @@ import {
 } from "../types/pipeline.js";
 import { Specification, parseSpecification } from "../types/specification.js";
 import { loadConfig, saveConfig, isCIInitialized, initCI } from "../core/config.js";
+import { getAgent } from "./index.js";
+import { IntelligenceBackend, BackendUnavailableError } from "../backends/types.js";
 
 export interface GitAgentContext extends AgentContext {
   gitContext: GitContext;
@@ -26,8 +28,9 @@ export interface GitAgentContext extends AgentContext {
 }
 
 export class OrchestratorAgent extends BaseAgent {
-  readonly name = "orchestrator";
+  readonly name: AgentName = "orchestrator";
   readonly description = "Top-level autonomous controller that coordinates the full CI pipeline";
+  readonly workflow = "run";
 
   private config: CIConfig;
   private pipelineState: PipelineState | null = null;
@@ -39,6 +42,13 @@ export class OrchestratorAgent extends BaseAgent {
   private currentMilestone: string;
   private phaseResults: PhaseResult[] = [];
 
+  private static readonly STAGE_AGENT_MAP: Partial<Record<PipelineStage, AgentName>> = {
+    research: "researcher",
+    plan: "planner",
+    execute: "executor",
+    verify: "verifier",
+  };
+
   constructor(config?: CIConfig) {
     super();
     this.config = config || loadConfig(process.cwd());
@@ -149,6 +159,32 @@ export class OrchestratorAgent extends BaseAgent {
     context: AgentContext
   ): Promise<PhaseResult> {
     const stageStart = Date.now();
+    const agentName = OrchestratorAgent.STAGE_AGENT_MAP[stage];
+
+    if (agentName && context.backend) {
+      this.log(`Delegating ${stage} to ${agentName} agent via backend...`);
+      try {
+        const agent = getAgent(agentName);
+        const result = await agent.execute(context);
+        return {
+          phase: this.pipelineState!.current_phase,
+          stage,
+          success: result.success,
+          artifacts_created: Array.isArray(result.artifacts_created) ? result.artifacts_created : [],
+          decisions_made: result.decisions,
+          escalations_raised: result.escalations,
+          duration_ms: Date.now() - stageStart,
+          error: result.error,
+        };
+      } catch (err) {
+        if (err instanceof BackendUnavailableError) {
+          this.warn(`Backend unavailable for ${stage}, falling back to mechanical execution`);
+        } else {
+          this.warn(`Agent ${agentName} failed for ${stage}: ${err instanceof Error ? err.message : String(err)}`);
+        }
+      }
+    }
+
     let decisionsMade = 0;
     let escalationsRaised = 0;
     const artifactsCreated: string[] = [];