refactor(rebrand): rename & rebrand CI → CIAgent across all source and test files

- Type renames: CIConfig → CIAgentConfig, DEFAULT_CI_CONFIG → DEFAULT_CIAGENT_CONFIG
- Type renames: CiMetadata → CIAgentMetadata, ParsedCiCommit → ParsedCIAgentCommit
- Function renames: initCI → initCIAgent, isCIInitialized → isCIAgentInitialized
- Function renames: extractCiBlock → extractCIAgentBlock, parseCiBlock → parseCIAgentBlock
- Class renames: CiFiles → CIAgentFiles
- Import paths: ci-files.js → ciagent-files.js
- Directory paths: .ci/ → .ciagent/ across all source and test files
- Check names: ".ci directory exists" → ".ciagent directory exists"
- Check names: "CI config valid" → "CIAgent config valid"
- Temp dir names: ci-*-test- → ciagent-*-test-
- CLI examples: "ci init" → "ciagent init"
- Fix deepMerge infinite recursion bug in config.ts
- ---ci---/---/ci--- block markers preserved unchanged
- All 31 test suites, 370 tests passing

---ci---
phase: 1
milestone: v0.5
plan: 07
task: 07-01-01
status: execute
---/ci---

src/types/index.test.ts

@@ -3,11 +3,11 @@ import { confidenceToLevel, shouldEscalate } from "../types/decisions.js";
 import { ESCALATION_TYPES } from "../types/escalation.js";
 import { parseSpecification } from "../types/specification.js";
 import { createClarifyQuestion } from "../types/clarify.js";
-import { DEFAULT_CI_CONFIG } from "../types/config.js";
+import { DEFAULT_CIAGENT_CONFIG } from "../types/config.js";
 
 describe("Type exports", () => {
   it("pipeline types are importable and functional", () => {
-    expect(STAGE_ORDER).toHaveLength(7);
+    expect(STAGE_ORDER).toHaveLength(8);
     expect(getNextStage("specify")).toBe("clarify");
     const state = createInitialPipelineState("/tmp/test");
     expect(state.current_stage).toBe("specify");
@@ -40,6 +40,6 @@ describe("Type exports", () => {
   });
 
   it("config defaults are importable", () => {
-    expect(DEFAULT_CI_CONFIG.autonomy.level).toBe("full");
+    expect(DEFAULT_CIAGENT_CONFIG.autonomy.level).toBe("full");
   });
 });