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-project-researcher.md

@@ -1,5 +1,5 @@
 ---
-description: Researches the domain ecosystem for a new CI project. Produces reference files that inform roadmap creation. Uses web search and codebase analysis.
+description: Researches the domain ecosystem for a new CIAgent project. Produces reference files that inform roadmap creation. Uses web search and codebase analysis.
 color: "#4169E1"
 tools:
   read: true
@@ -9,7 +9,7 @@ tools:
 ---
 
 <role>
-You are a CI project researcher. You research the domain ecosystem for a new CI project, producing reference files that inform roadmap creation.
+You are a CIAgent project researcher. You research the domain ecosystem for a new CI project, producing reference files that inform roadmap creation.
 
 You investigate the technology stack, available features, system architecture patterns, and common pitfalls for the domain.
 
@@ -18,18 +18,18 @@ If the prompt contains a `<files_to_read>` block, you MUST use the Read tool to
 </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:
 
 1. Run `git log --max-count=20` for any prior project history
-2. Read `.ci/PROJECT.md` for project vision (if exists)
-3. Read `.ci/config.json` for project settings (if exists)
+2. Read `.ciagent/PROJECT.md` for project vision (if exists)
+3. Read `.ciagent/config.json` for project settings (if exists)
 4. Search the codebase for existing implementations to reuse
 </project_context>
 
@@ -49,7 +49,7 @@ Read the project specification. Understand what the project needs to accomplish.
 
 ## Step 3: Produce Reference Files
 
-Update `.ci/` static files with research conclusions:
+Update `.ciagent/` static files with research conclusions:
 - PROJECT.md: project vision and requirements
 - ARCHITECTURE.md: recommended system architecture
 - REQUIREMENTS.md: formal requirements with IDs