feat(mcp): codeman mcp, a Model Context Protocol server for any MCP client

Agents pick tools from MCP clients and registries, and Codeman had no MCP
surface: an assistant in Claude Desktop, Cursor, Codex or Gemini CLI could
not start or drive Codeman sessions without hand-written HTTP calls.

`codeman mcp` is a stdio MCP server and a CLIENT of the existing HTTP API
(it reuses codeman agent's transport and guards; no new route). Seven
tools: list_sessions, start_session, send_prompt, wait_for_session,
read_output, interrupt_session, delete_session.

- Dual-era: answers the legacy initialize handshake (2024-11-05 to
  2025-11-25) and the 2026-07-28 revision (per-request _meta,
  server/discover, resultType, and the ttlMs/cacheScope hints a modern
  tools/list must carry: Claude Code 2.1.296 drops every tool without
  them).
- Never guesses a server: the URL comes from --url or CODEMAN_API_URL.
  Unconfigured, it still lists its tools and every call says how to
  configure it.
- Prompting, interrupting and deleting are limited to sessions the process
  started (or, inside a Codeman pane, that session's own workers) unless
  --allow-any-session; never its own session. Control bytes are refused
  before any request.
- Waits default to 45 s (Codex's MCP tool timeout is 60 s), max 600 s.
- read_output returns text only: a client that prefers structuredContent
  otherwise showed the model metadata instead of the output.
- config/mcp-registry/server.json and package.json mcpName prepare the
  official MCP registry listing; sync-plugin.mjs keeps its version.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

config/mcp-registry/server.json

@@ -0,0 +1,43 @@
+{
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json",
+  "name": "io.github.Ark0N/codeman",
+  "title": "Codeman",
+  "description": "Start, prompt and read AI coding agent sessions (Claude Code, Codex, Gemini CLI and more) in Codeman",
+  "version": "1.41.0",
+  "websiteUrl": "https://getcodeman.com",
+  "repository": {
+    "url": "https://github.com/Ark0N/Codeman",
+    "source": "github"
+  },
+  "packages": [
+    {
+      "registryType": "npm",
+      "identifier": "aicodeman",
+      "version": "1.41.0",
+      "transport": {
+        "type": "stdio"
+      },
+      "packageArguments": [
+        {
+          "type": "positional",
+          "value": "mcp"
+        }
+      ],
+      "environmentVariables": [
+        {
+          "name": "CODEMAN_API_URL",
+          "description": "Where your Codeman server runs, for example https://127.0.0.1:3000. Never guessed.",
+          "isRequired": true,
+          "format": "string"
+        },
+        {
+          "name": "CODEMAN_PASSWORD",
+          "description": "Codeman's HTTP Basic password, when the server has one.",
+          "isRequired": false,
+          "isSecret": true,
+          "format": "string"
+        }
+      ]
+    }
+  ]
+}