fix(P01): replace hardcoded phase=1 in orchestrator and fix getDecisions double-fetch

---ci---
project: ci
phase: 1
milestone: v0.8
status: in_progress
decisions:
  - id: D-021
    decision: 6-phase wave-ordered vertical slices for v0.8
    rationale: Each phase independently demoable; critical fixes first
    confidence: 0.90
requirements:
  covered: [FIX-01, FIX-06]
---/ci---

FIX-01: Replace 5 hardcoded phase=1 literals in orchestrator.ts mechanical
execution path with this.pipelineState!.current_phase. The orchestrator
correctly tracks current_phase but commits always embedded literal 1.

FIX-06: Replace getDecisions() redundant double-fetch with single
getRecentCommits(50) call, delegating to existing getDecisionsFromCommits().
Old code called getRecentCommits(50) once per grep match entry (O(N*M)
when it should be O(1)).

src/agents/orchestrator.ts

@@ -500,7 +500,7 @@ export class OrchestratorAgent extends BaseAgent {
 
       case "research": {
         this.log("Researching project domain...");
-        this.decisionEngine!.setPhase(1);
+        this.decisionEngine!.setPhase(this.pipelineState!.current_phase);
 
         const archMd = this.ciFiles!.readArchitectureMd();
         if (!archMd) {
@@ -519,7 +519,7 @@ export class OrchestratorAgent extends BaseAgent {
 
         if (this.config.git.auto_commit && this.gitContext!.isGitRepo()) {
           const researchCommit = CommitBuilder.buildResearchCommit(
-            1,
+            this.pipelineState!.current_phase,
             this.currentMilestone,
             "initial domain research",
             ["Research completed. Key findings in .ciagent/ARCHITECTURE.md and .ciagent/PROJECT.md updates."]
@@ -543,7 +543,7 @@ export class OrchestratorAgent extends BaseAgent {
         this.log("Planning phase execution...");
 
         if (this.config.git.branching_strategy === "phase" && this.gitBranch && this.gitContext!.isGitRepo()) {
-          this.gitBranch.createPhaseBranch(1, "initial-phase");
+          this.gitBranch.createPhaseBranch(this.pipelineState!.current_phase, "initial-phase");
         }
 
         this.pipelineState!.plan_completed = true;
@@ -623,7 +623,7 @@ export class OrchestratorAgent extends BaseAgent {
 
         if (this.config.git.auto_commit && this.gitContext!.isGitRepo()) {
           const verifyCommit = CommitBuilder.buildVerifyCommit({
-            phase: 1,
+            phase: this.pipelineState!.current_phase,
             milestone: this.currentMilestone,
             subject: "automated verification passed",
             requirements: { covered: [], partial: [] },
@@ -646,7 +646,7 @@ export class OrchestratorAgent extends BaseAgent {
 
         if (this.config.git.auto_commit && this.gitContext!.isGitRepo()) {
           const completionCommit = CommitBuilder.buildPhaseCompletionCommit({
-            phase: 1,
+            phase: this.pipelineState!.current_phase,
             milestone: this.currentMilestone,
             phaseName: "initial-phase",
             tasksCompleted: 0,