fix(opencode): install to ~/.config/opencode instead of ~/.opencode

OpenCode natively uses ~/.config/opencode per XDG conventions. The
install target was writing to ~/.opencode, which only worked on systems
where that path happened to be symlinked to ~/.config/opencode. The MCP
inventory reader already looked in ~/.config/opencode, so the installer
and reader were inconsistent.

scripts/install-apply.js

@@ -39,7 +39,7 @@ Targets:
   antigravity  - Install rules, workflows, skills, and agents to ./.agents/
   codex        - Install shared agents/config into ~/.codex/
   gemini       - Install project-local Gemini config into ./.gemini/
-  opencode     - Install shared commands/hooks/config into ~/.opencode/
+  opencode     - Install shared commands/hooks/config into ~/.config/opencode/
   codebuddy    - Install commands, agents, skills, and flattened rules into ./.codebuddy/
   joycode      - Install commands, agents, skills, and flattened rules into ./.joycode/
   qwen         - Install commands, agents, skills, rules, and Qwen config into ~/.qwen/

scripts/lib/install-targets/opencode-home.js

@@ -83,7 +83,7 @@ module.exports = createInstallTargetAdapter({
   id: 'opencode-home',
   target: 'opencode',
   kind: 'home',
-  rootSegments: ['.opencode'],
+  rootSegments: ['.config', 'opencode'],
   installStatePathSegments: ['ecc-install-state.json'],
   nativeRootRelativePath: '.opencode',
   validate: defaultValidateOpencodeHome,