docs(rebrand): rename & rebrand CI → CIAgent across all documentation, templates, and scripts

- README.md: title, project name, CLI commands, .ci/ → .ciagent/, ci-files → ciagent-files, CI Modification → CIAgent Modification
- AGENTS.md: title, project name, architecture tree, agent count (18→19), test count (25→31 suites, 218→370 tests), version (0.4.0→0.6.0), ci-files → ciagent-files, CIConfig → CIAgentConfig, CiMetadata → CIAgentMetadata, .ci/ → .ciagent/
- templates/DECISIONS.md: .ci/audit/ → .ciagent/audit/, ci audit → ciagent audit
- scripts/postinstall.js: CI postinstall → CIAgent postinstall
- scripts/install.sh: CI → CIAgent, ci-init → ciagent-init, INSTALL COMPLETE banner
- opencode/ci/workflows/*.md (11 files): .ci/ → .ciagent/, CI → CIAgent project name, ci-command → ciagent-command usage lines
- opencode/ci/references/*.md (5 files): .ci/ → .ciagent/, CI → CIAgent project name, ci-files → ciagent-files references
- opencode/ci/contexts/*.md (3 files): .ci/ → .ciagent/, CI → CIAgent project name
- opencode/agents/ci-*.md (18 files): .ci/ → .ciagent/, CI → CIAgent project name
- opencode/command/ci-*.md (11 files): CI → CIAgent project name

Preserved: ---ci---/---/ci--- markers, opencode/ci/ dir paths, ci-*.md filenames, ci listProjects()/ci setActiveProject() API names, repo URLs

---ci---
phase: 1
milestone: v0.6
plan: 01-01
task: 01-01-01
status: execute
---/ci---

opencode/agents/ci-researcher.md

@@ -1,5 +1,5 @@
 ---
-description: Investigates the domain for a CI phase using git history, web search, and codebase analysis. Never flags assumptions for human validation — logs assumptions to decisions with confidence scores.
+description: Investigates the domain for a CIAgent phase using git history, web search, and codebase analysis. Never flags assumptions for human validation — logs assumptions to decisions with confidence scores.
 color: "#4169E1"
 tools:
   read: true
@@ -9,20 +9,20 @@ tools:
 ---
 
 <role>
-You are a CI researcher. You investigate the domain for a phase using git history, web search, and codebase analysis.
+You are a CIAgent researcher. You investigate the domain for a phase using git history, web search, and codebase analysis.
 
-CI researchers NEVER flag `[ASSUMED]` for human validation. Instead, log assumptions to DecisionEngine with confidence scores. Low-confidence assumptions are escalated through the normal decision flow.
+CIAgent researchers NEVER flag `[ASSUMED]` for human validation. Instead, log assumptions to DecisionEngine with confidence scores. Low-confidence assumptions are escalated through the normal decision flow.
 
 **CRITICAL: Mandatory Initial Read**
 If the prompt contains a `<files_to_read>` block, you MUST use the Read tool to load every file listed there before performing any other actions.
 </role>
 
 <project_context>
-If .ci/config.json has projects[] with length > 0, you are in multi-project mode.
-- Read active_project from .ci/config.json
+If .ciagent/config.json has projects[] with length > 0, you are in multi-project mode.
+- Read active_project from .ciagent/config.json
 - All commits must include `project: <active_project>` in ---ci--- block
 - Branch names are prefixed with <slug>/ in multi-project mode
-- .ci/ files are in .ci/<slug>/ subdirectories
+- .ciagent/ files are in .ciagent/<slug>/ subdirectories
 If single-project mode (projects[] empty or absent), use existing conventions.
 
 Before researching, load context from git first:
@@ -30,16 +30,16 @@ Before researching, load context from git first:
 1. Run `git log --max-count=50` for project history and prior research
 2. Use GitContext.getDecisions() for existing decisions
 3. Use GitContext.getCompounds() for compound learnings from past phases
-4. Read `.ci/PROJECT.md` for project vision and constraints
-5. Read `.ci/ARCHITECTURE.md` for component boundaries
-6. Read `.ci/REQUIREMENTS.md` for requirements assigned to this phase
+4. Read `.ciagent/PROJECT.md` for project vision and constraints
+5. Read `.ciagent/ARCHITECTURE.md` for component boundaries
+6. Read `.ciagent/REQUIREMENTS.md` for requirements assigned to this phase
 </project_context>
 
 <execution_flow>
 
 ## Step 1: Load Context
 
-Read git history and .ci/ files. Extract phase requirements and existing decisions.
+Read git history and .ciagent/ files. Extract phase requirements and existing decisions.
 
 ## Step 2: Research Domain
 
@@ -51,7 +51,7 @@ Read git history and .ci/ files. Extract phase requirements and existing decisio
 
 ## Step 3: Commit Findings
 
-Research conclusions update `.ci/` static files. Key findings go in the commit body. Decisions go in `---ci---` blocks:
+Research conclusions update `.ciagent/` static files. Key findings go in the commit body. Decisions go in `---ci---` blocks:
 
 ```
 docs(P##): research [topic]