rebrand: rename AutoCoder to AutoForge across entire codebase

Complete project rebrand from AutoCoder to AutoForge, touching 62 files
across Python backend, FastAPI server, React UI, documentation, config,
and CI/CD.

Key changes:
- Rename autocoder_paths.py -> autoforge_paths.py with backward-compat
  migration from .autocoder/ -> .autoforge/ directories
- Update registry.py to migrate ~/.autocoder/ -> ~/.autoforge/ global
  config directory with fallback support
- Update security.py with fallback reads from legacy .autocoder/ paths
- Rename .claude/commands and skills from gsd-to-autocoder-spec to
  gsd-to-autoforge-spec
- Update all Python modules: client, prompts, progress, agent,
  orchestrator, server routers and services
- Update React UI: package.json name, index.html title, localStorage
  keys, all documentation sections, component references
- Update start scripts (bat/sh/py), examples, and .env.example
- Update CLAUDE.md and README.md with new branding and paths
- Update test files for new .autoforge/ directory structure
- Transfer git remote from leonvanzyl/autocoder to
  AutoForgeAI/autoforge

Backward compatibility preserved: legacy .autocoder/ directories are
auto-detected and migrated on next agent start. Config fallback chain
checks both new and old paths.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

client.py

@@ -382,7 +382,7 @@ def create_client(
     project_dir.mkdir(parents=True, exist_ok=True)
 
     # Write settings to a file in the project directory
-    from autocoder_paths import get_claude_settings_path
+    from autoforge_paths import get_claude_settings_path
     settings_file = get_claude_settings_path(project_dir)
     settings_file.parent.mkdir(parents=True, exist_ok=True)
     with open(settings_file, "w") as f:
@@ -450,7 +450,7 @@ def create_client(
 
     # Build environment overrides for API endpoint configuration
     # These override system env vars for the Claude CLI subprocess,
-    # allowing AutoCoder to use alternative APIs (e.g., GLM) without
+    # allowing AutoForge to use alternative APIs (e.g., GLM) without
     # affecting the user's global Claude Code settings
     sdk_env = {}
     for var in API_ENV_VARS: