feat: Add JSONC support for oh-my-opencode config files (#275)

Uses Microsoft's jsonc-parser package for reliable JSONC parsing:
- oh-my-opencode.jsonc (preferred) or oh-my-opencode.json
- Supports line comments (//), block comments (/* */), and trailing commas
- Better error reporting with line/column positions

Core changes:
- Added jsonc-parser dependency (Microsoft's VS Code parser)
- Shared JSONC utilities (parseJsonc, parseJsoncSafe, readJsoncFile, detectConfigFile)
- Main plugin config loader uses detectConfigFile for .jsonc priority
- CLI config manager supports JSONC parsing

Comprehensive test suite with 18 tests for JSONC parsing.

Fixes #265

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: sisyphus-dev-ai <sisyphus-dev-ai@users.noreply.github.com>

package.json

@@ -59,6 +59,7 @@
     "@opencode-ai/sdk": "^1.0.162",
     "commander": "^14.0.2",
     "hono": "^4.10.4",
+    "jsonc-parser": "^3.3.1",
     "picocolors": "^1.1.1",
     "picomatch": "^4.0.2",
     "xdg-basedir": "^5.1.0",