Add meta-tools, collections, and attribution features

Meta-tools:
- Add ToolStep dataclass for tools calling other tools
- Implement execute_tool_step() with recursion depth limiting
- Add check_dependencies() for validating tool dependencies
- Add 'cmdforge check' command for dependency verification

Collections:
- Add collections API endpoints and database schema
- Create collections web UI (list and detail pages)
- Add collections to navigation header and homepage
- Document collections in REGISTRY.md

Attribution:
- Add source attribution fields to tool detail page
- Document source types (original, adapted, imported)
- Add license field documentation

Documentation updates across README, DESIGN.md, REGISTRY.md,
and new META_TOOLS.md design document.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

src/cmdforge/web/templates/components/header.html

@@ -22,6 +22,10 @@
                    class="px-3 py-2 rounded-md text-sm font-medium hover:bg-slate-700 transition-colors {% if request.path.startswith('/tools') %}bg-slate-700{% endif %}">
                     Registry
                 </a>
+                <a href="{{ url_for('web.collections') }}"
+                   class="px-3 py-2 rounded-md text-sm font-medium hover:bg-slate-700 transition-colors {% if request.path.startswith('/collections') %}bg-slate-700{% endif %}">
+                    Collections
+                </a>
                 <a href="{{ url_for('forum.index') }}"
                    class="px-3 py-2 rounded-md text-sm font-medium hover:bg-slate-700 transition-colors {% if request.path.startswith('/forum') %}bg-slate-700{% endif %}">
                     Forum
@@ -119,6 +123,10 @@
                    class="block px-3 py-2 rounded-md text-base font-medium hover:bg-slate-700 {% if request.path.startswith('/tools') %}bg-slate-700{% endif %}">
                     Registry
                 </a>
+                <a href="{{ url_for('web.collections') }}"
+                   class="block px-3 py-2 rounded-md text-base font-medium hover:bg-slate-700 {% if request.path.startswith('/collections') %}bg-slate-700{% endif %}">
+                    Collections
+                </a>
                 <a href="{{ url_for('forum.index') }}"
                    class="block px-3 py-2 rounded-md text-base font-medium hover:bg-slate-700 {% if request.path.startswith('/forum') %}bg-slate-700{% endif %}">
                     Forum