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>

.claude/commands/gsd-to-autoforge-spec.md

@@ -0,0 +1,10 @@
+---
+allowed-tools: Read, Write, Bash, Glob, Grep
+description: Convert GSD codebase mapping to AutoForge app_spec.txt
+---
+
+# GSD to AutoForge Spec
+
+Convert `.planning/codebase/*.md` (from `/gsd:map-codebase`) to AutoForge's `.autoforge/prompts/app_spec.txt`.
+
+@.claude/skills/gsd-to-autoforge-spec/SKILL.md