feat: add proto rm/remove command to uninstall protocol (#3)

* feat: add proto rm/remove command to uninstall protocol

Implement cueme proto rm/remove command as the reverse operation of
cueme proto apply. This allows users to cleanly remove the HAP protocol
from agent configuration files.

Features:
- Add protoRemove() function to remove managed blocks
- Support both 'rm' and 'remove' aliases
- Automatically delete file if it becomes empty after removal
- Preserve file content outside managed blocks
- Handle cases where file or managed block doesn't exist

Usage:
  cueme proto rm <agent>
  cueme proto remove <agent>

Examples:
  cueme proto rm windsurf
  cueme proto remove kiro

The command removes content between BEGIN_MARKER and END_MARKER,
preserving any other content in the file. If the file only contains
the managed block, it will be deleted entirely.

* fix: address code review feedback

Address all feedback from code review:

Must-fix items:
1. Remove unused 'exists' variable in protoRemove()
2. Throw error when file deletion fails instead of returning ok
   - Changed from 'ok: ... but failed to delete' to throwing Error
   - This ensures non-zero exit code and proper error handling

Improvements:
3. Removed trimEnd() to preserve original file formatting
   - Keep trailing whitespace/newlines as they were
   - Only remove the managed block itself

The function now:
- Cleanly removes managed blocks
- Preserves original file formatting
- Properly reports errors when file deletion fails
- Has no unused variables

Author: XiangqianHuang

src/cli.js

@@ -1,7 +1,7 @@
 const { readAllStdin } = require('./io');
 const { handleCommand } = require('./handler');
 const { parseTagBlocksEnvelope } = require('./envelope');
-const { protoApply, protoInit, protoLs, protoPath, protoRender } = require('./proto');
+const { protoApply, protoRemove, protoInit, protoLs, protoPath, protoRender } = require('./proto');
 const pkg = require('../package.json');
 const fs = require('fs');
 const path = require('path');
@@ -99,6 +99,7 @@ async function main() {
         '  cueme -p|--protocol',
         '  cueme proto <agent>',
         '  cueme proto apply <agent>',
+        '  cueme proto rm|remove <agent>',
         '  cueme proto init',
         '  cueme proto ls',
         '  cueme proto path <agent>',
@@ -258,6 +259,17 @@ async function main() {
         return;
       }
 
+      if (action === 'rm' || action === 'remove') {
+        const agent = pos[1];
+        if (!agent) {
+          process.stderr.write('error: missing <agent>\n');
+          process.exitCode = 2;
+          return;
+        }
+        process.stdout.write(protoRemove(String(agent)) + '\n');
+        return;
+      }
+
       if (action === 'path') {
         const agent = pos[1];
         if (!agent) {

src/proto.js

@@ -399,6 +399,48 @@ function protoApply(agent) {
   return `ok: applied to ${targetPath}`;
 }
 
+function protoRemove(agent) {
+  const cfg = readConfigOrThrow({ auto_init: true });
+  const targetPath = resolveTargetPath({ cfg, agent });
+
+  let existing = '';
+  try {
+    existing = fs.readFileSync(targetPath, 'utf8');
+  } catch {
+    return `ok: file does not exist: ${targetPath}`;
+  }
+
+  const beginMatch = existing.match(BEGIN_MARKER_RE);
+  const endMatch = existing.match(END_MARKER_RE);
+
+  if (!beginMatch || !endMatch || endMatch.index <= beginMatch.index) {
+    return `ok: no managed block found in: ${targetPath}`;
+  }
+
+  const beginIdx = beginMatch.index;
+  const endIdx = endMatch.index;
+  const endLen = endMatch[0].length;
+
+  const before = existing.slice(0, beginIdx);
+  const after = existing.slice(endIdx + endLen);
+
+  const eol = detectEol(existing);
+  const afterTrim = after.startsWith(eol) ? after.slice(eol.length) : after;
+  const out = before + afterTrim;
+
+  if (out.trim().length === 0) {
+    try {
+      fs.unlinkSync(targetPath);
+      return `ok: removed managed block and deleted empty file: ${targetPath}`;
+    } catch (err) {
+      throw new Error(`error: failed to delete file after removing managed block: ${targetPath}: ${err.message}`);
+    }
+  }
+
+  fs.writeFileSync(targetPath, out, 'utf8');
+  return `ok: removed managed block from: ${targetPath}`;
+}
+
 function protoInit() {
   const { created, path: p, detected } = initConfigIfMissing();
   if (!created) return `ok: exists ${p}`;
@@ -417,6 +459,7 @@ module.exports = {
   END_MARKER,
   getPlatformKey,
   protoApply,
+  protoRemove,
   protoInit,
   protoLs,
   protoPath,