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>

registry.py

@@ -3,7 +3,7 @@ Project Registry Module
 =======================
 
 Cross-platform project registry for storing project name to path mappings.
-Uses SQLite database stored at ~/.autocoder/registry.db.
+Uses SQLite database stored at ~/.autoforge/registry.db.
 """
 
 import logging
@@ -23,6 +23,22 @@ from sqlalchemy.orm import DeclarativeBase, sessionmaker
 logger = logging.getLogger(__name__)
 
 
+def _migrate_registry_dir() -> None:
+    """Migrate ~/.autocoder/ to ~/.autoforge/ if needed.
+
+    Provides backward compatibility by automatically renaming the old
+    config directory to the new location on first access.
+    """
+    old_dir = Path.home() / ".autocoder"
+    new_dir = Path.home() / ".autoforge"
+    if old_dir.exists() and not new_dir.exists():
+        try:
+            old_dir.rename(new_dir)
+            logger.info("Migrated registry directory: ~/.autocoder/ -> ~/.autoforge/")
+        except Exception:
+            logger.warning("Failed to migrate ~/.autocoder/ to ~/.autoforge/", exc_info=True)
+
+
 # =============================================================================
 # Model Configuration (Single Source of Truth)
 # =============================================================================
@@ -120,12 +136,15 @@ _engine_lock = threading.Lock()
 
 def get_config_dir() -> Path:
     """
-    Get the config directory: ~/.autocoder/
+    Get the config directory: ~/.autoforge/
+
+    Automatically migrates from ~/.autocoder/ if needed.
 
     Returns:
-        Path to ~/.autocoder/ (created if it doesn't exist)
+        Path to ~/.autoforge/ (created if it doesn't exist)
     """
-    config_dir = Path.home() / ".autocoder"
+    _migrate_registry_dir()
+    config_dir = Path.home() / ".autoforge"
     config_dir.mkdir(parents=True, exist_ok=True)
     return config_dir