feat: adopt TOML and Agent Skill approach for Gemini CLI extension

- Added `gemini-extension.json` and `commands/opencli.toml` to register OpenCLI as a command-line tool extension for Gemini CLI using a declarative configuration.
- Added `skills/opencli/SKILL.md` (via symlink) to provide the AI agent with specific instructions and workflow context on how to use OpenCLI.
- Dropped the experimental programmatic tools implementation in favor of this simpler, maintainable architecture.

Author: dull-bird

commands/opencli.toml

@@ -0,0 +1,16 @@
+description = "Use OpenCLI to get data or interact with sites from natural language. Make any website or Electron App your CLI."
+prompt = """
+You are an expert at OpenCLI. The user wants to use OpenCLI to fulfill their request: {{args}}
+
+Here are the commands you have available:
+```
+!{npx tsx src/main.ts list}
+```
+
+1. Understand the user's intent, and identify the single most relevant opencli command.
+2. Determine the exact `opencli` shell command needed (including any required arguments). 
+   Note: OpenCLI commands usually use standard POSIX flag structure. E.g. `npx tsx src/main.ts twitter search "my query" --limit 10`
+3. Execute the command using the `run_shell_command` tool. Use `npx tsx src/main.ts` as the executable since we are running within the extension repository.
+4. If the requested site/command doesn't appear in the list, you might need to use `npx tsx src/main.ts generate` to create the adapter first.
+5. Provide a brief answer interpreting the output of the opencli execution, or format it nicely for the user.
+"""

gemini-extension.json

@@ -0,0 +1,5 @@
+{
+  "name": "opencli",
+  "version": "1.2.6",
+  "description": "OpenCLI Gemini Extension"
+}

package.json

@@ -34,7 +34,8 @@
     "test:e2e": "vitest run --project e2e",
     "docs:dev": "vitepress dev docs",
     "docs:build": "vitepress build docs",
-    "docs:preview": "vitepress preview docs"
+    "docs:preview": "vitepress preview docs",
+    "version": "node -e \"const fs=require('fs'); const pkg=require('./package.json'); const ext=require('./gemini-extension.json'); ext.version=pkg.version; fs.writeFileSync('./gemini-extension.json', JSON.stringify(ext, null, 2) + '\\n');\" && git add gemini-extension.json"
   },
   "keywords": [
     "cli",

skills/opencli/SKILL.md

@@ -0,0 +1 @@
+../../SKILL.md