feat: add TouchDesigner integration skill

New skill: creative/touchdesigner — control a running TouchDesigner
instance via REST API. Build real-time visual networks programmatically.

Architecture:
  Hermes Agent -> HTTP REST (curl) -> TD WebServer DAT -> TD Python env

Key features:
- Custom API handler (scripts/custom_api_handler.py) that creates a
  self-contained WebServer DAT + callback in TD. More reliable than the
  official mcp_webserver_base.tox which frequently fails module imports.
- Discovery-first workflow: never hardcode TD parameter names. Always
  probe the running instance first since names change across versions.
- Persistent setup: save the TD project once with the API handler baked
  in. TD auto-opens the last project on launch, so port 9981 is live
  with zero manual steps after first-time setup.
- Works via curl in execute_code (no MCP dependency required).
- Optional MCP server config for touchdesigner-mcp-server npm package.

Skill structure (2823 lines total):
  SKILL.md (209 lines) — setup, workflow, key rules, operator reference
  references/pitfalls.md (276 lines) — 24 hard-won lessons
  references/operators.md (239 lines) — all 6 operator families
  references/network-patterns.md (589 lines) — audio-reactive, generative,
    video processing, GLSL, instancing, live performance recipes
  references/mcp-tools.md (501 lines) — 13 MCP tool schemas
  references/python-api.md (443 lines) — TD Python scripting patterns
  references/troubleshooting.md (274 lines) — connection diagnostics
  scripts/custom_api_handler.py (140 lines) — REST API handler for TD
  scripts/setup.sh (152 lines) — prerequisite checker

Tested on TouchDesigner 099 Non-Commercial (macOS/darwin).

skills/creative/touchdesigner/scripts/custom_api_handler.py

@@ -0,0 +1,140 @@
+"""
+Custom API Handler for TouchDesigner WebServer DAT
+===================================================
+Use this when mcp_webserver_base.tox fails to load its modules
+(common — the .tox relies on relative paths to a modules/ folder
+that often break during import).
+
+Paste into TD Textport or run via exec(open('...').read()):
+  Creates a WebServer DAT + Text DAT callback handler on port 9981.
+  Implements the core endpoints the MCP server expects.
+
+After running, test with:
+  curl http://127.0.0.1:9981/api/td/server/td
+"""
+
+root = op('/project1')
+
+# Remove broken webserver if present
+old = op('/project1/mcp_webserver_base')
+if old and old.valid:
+    old.destroy()
+
+# Create WebServer DAT
+ws = root.create(webserverDAT, 'api_server')
+ws.par.port = 9981
+ws.par.active = True
+ws.nodeX = -800; ws.nodeY = 500
+
+# Create callback handler
+cb = root.create(textDAT, 'api_handler')
+cb.nodeX = -800; cb.nodeY = 400
+cb.text = r'''
+import json, traceback, io, sys
+
+def onHTTPRequest(webServerDAT, request, response):
+    uri = request.get('uri', '')
+    method = request.get('method', 'GET')
+    response['statusCode'] = 200
+    response['statusReason'] = 'OK'
+    response['headers'] = {'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*'}
+
+    try:
+        # TD sends POST body as bytes in request['data']
+        raw = request.get('data', request.get('body', ''))
+        if isinstance(raw, bytes):
+            raw = raw.decode('utf-8')
+        body = {}
+        if raw and isinstance(raw, str) and raw.strip():
+            body = json.loads(raw)
+        pars = request.get('pars', {})
+
+        if uri == '/api/td/server/td':
+            response['data'] = json.dumps({
+                'version': str(app.version),
+                'osName': sys.platform,
+                'apiVersion': '1.4.3',
+                'product': 'TouchDesigner'
+            })
+
+        elif uri == '/api/td/server/exec':
+            script = body.get('script', '')
+            old_stdout = sys.stdout
+            sys.stdout = buf = io.StringIO()
+            result_val = None
+            err_text = ''
+            try:
+                globs = {'op': op, 'ops': ops, 'me': webServerDAT, 'parent': parent,
+                         'project': project, 'td': td, 'result': None,
+                         'app': app, 'absTime': absTime}
+                lines = script.strip().split('\n')
+                if len(lines) == 1:
+                    try:
+                        result_val = eval(script, globs)
+                    except SyntaxError:
+                        exec(script, globs)
+                        result_val = globs.get('result')
+                else:
+                    exec(script, globs)
+                    result_val = globs.get('result')
+            except Exception as e:
+                err_text = traceback.format_exc()
+            finally:
+                captured = buf.getvalue()
+                sys.stdout = old_stdout
+            response['data'] = json.dumps({
+                'result': _serialize(result_val),
+                'stdout': captured,
+                'stderr': err_text
+            })
+
+        elif uri == '/api/nodes':
+            pp = pars.get('parentPath', ['/project1'])[0]
+            p = op(pp)
+            nodes = []
+            if p:
+                for c in p.children:
+                    nodes.append({'name': c.name, 'path': c.path,
+                                  'opType': c.OPType, 'family': c.family})
+            response['data'] = json.dumps({'data': nodes})
+
+        elif uri == '/api/nodes/errors':
+            np = pars.get('nodePath', ['/project1'])[0]
+            n = op(np)
+            errors = []
+            if n:
+                def _collect(node, depth=0):
+                    if depth > 10: return
+                    e = node.errors()
+                    if e:
+                        errors.append({'nodePath': node.path, 'nodeName': node.name,
+                                       'opType': node.OPType, 'errors': str(e)})
+                    if hasattr(node, 'children'):
+                        for c in node.children: _collect(c, depth+1)
+                _collect(n)
+            response['data'] = json.dumps({'data': errors, 'hasErrors': len(errors)>0,
+                                            'errorCount': len(errors)})
+
+        else:
+            response['statusCode'] = 404
+            response['data'] = json.dumps({'error': 'Unknown: ' + uri})
+
+    except Exception as e:
+        response['statusCode'] = 500
+        response['data'] = json.dumps({'error': str(e), 'trace': traceback.format_exc()})
+
+    return response
+
+def _serialize(v):
+    if v is None: return None
+    if isinstance(v, (int, float, bool, str)): return v
+    if isinstance(v, (list, tuple)): return [_serialize(i) for i in v]
+    if isinstance(v, dict): return {str(k): _serialize(vv) for k, vv in v.items()}
+    return str(v)
+'''
+
+# Point webserver to callback
+ws.par.callbacks = cb.path
+
+print("Custom API server created on port 9981")
+print("Test: curl http://127.0.0.1:9981/api/td/server/td")