feat(codex): support slash controls and skill discovery (#545)

* feat(codex): resolve slash controls before sending to Codex

* feat(codex): discover commands and skills

* fix(codex): handle slash commands before attachments

* fix(codex): block remaining unsupported built-ins

web/src/lib/codexSlashCommands.test.ts

@@ -2,14 +2,19 @@ import { describe, expect, it } from 'vitest'
 import { findUnsupportedCodexBuiltinSlashCommand, getBuiltinSlashCommands } from './codexSlashCommands'
 
 describe('getBuiltinSlashCommands', () => {
-    it('does not expose codex built-ins in remote web mode', () => {
-        expect(getBuiltinSlashCommands('codex')).toEqual([])
+    it('exposes HAPI-supported codex built-ins in remote web mode', () => {
+        expect(getBuiltinSlashCommands('codex').map((command) => command.name)).toEqual(expect.arrayContaining([
+            'plan',
+            'status',
+            'execute',
+            'effort',
+            'permission',
+        ]))
     })
 })
 
 describe('findUnsupportedCodexBuiltinSlashCommand', () => {
     it('detects unsupported codex built-ins', () => {
-        expect(findUnsupportedCodexBuiltinSlashCommand('/status', [])).toBe('status')
         expect(findUnsupportedCodexBuiltinSlashCommand('  /diff ', [])).toBe('diff')
     })
 

web/src/lib/codexSlashCommands.ts

@@ -11,9 +11,18 @@ const BUILTIN_COMMANDS: Record<string, SlashCommand[]> = {
         { name: 'stats', description: 'Show your Claude Code usage statistics and activity', source: 'builtin' },
         { name: 'status', description: 'Show Claude Code status including version, model, account, and API connectivity', source: 'builtin' },
     ],
-    // Codex remote turns send slash-prefixed input as plain text to app-server.
-    // Hide built-ins here until remote slash command execution is implemented end-to-end.
-    codex: [],
+    codex: [
+        { name: 'help', description: 'Show supported HAPI Codex slash commands', source: 'builtin' },
+        { name: 'plan', description: 'Enable plan mode; use /plan off to return to default', source: 'builtin' },
+        { name: 'default', description: 'Return Codex collaboration mode to default', source: 'builtin' },
+        { name: 'execute', description: 'Return Codex collaboration mode to default', source: 'builtin' },
+        { name: 'status', description: 'Show current Codex session config', source: 'builtin' },
+        { name: 'model', description: 'Show or set Codex model, e.g. /model gpt-5.5', source: 'builtin' },
+        { name: 'reasoning', description: 'Show or set reasoning effort', source: 'builtin' },
+        { name: 'effort', description: 'Alias for /reasoning', source: 'builtin' },
+        { name: 'permissions', description: 'Show or set permission mode', source: 'builtin' },
+        { name: 'permission', description: 'Alias for /permissions', source: 'builtin' },
+    ],
     gemini: [
         { name: 'about', description: 'Show version info', source: 'builtin' },
         { name: 'clear', description: 'Clear the screen and conversation history', source: 'builtin' },
@@ -29,7 +38,6 @@ const UNSUPPORTED_CODEX_BUILTIN_COMMANDS = new Set([
     'compat',
     'undo',
     'diff',
-    'status',
 ])
 
 export function getBuiltinSlashCommands(agentType: string): SlashCommand[] {