chore: rebrand companion-os to clanker-agent

- Rename all package names from companion-* to clanker-*
- Update npm scopes from @mariozechner to @harivansh-afk
- Rename config directories .companion -> .clanker
- Rename environment variables COMPANION_* -> CLANKER_*
- Update all documentation, README files, and install scripts
- Rename package directories (companion-channels, companion-grind, companion-teams)
- Update GitHub URLs to harivansh-afk/clanker-agent
- Preserve full git history from companion-cloud monorepo

packages/coding-agent/clanker-out/docs/windows.md

@@ -0,0 +1,17 @@
+# Windows Setup
+
+Clanker requires a bash shell on Windows. Checked locations (in order):
+
+1. Custom path from `~/.clanker/agent/settings.json`
+2. Git Bash (`C:\Program Files\Git\bin\bash.exe`)
+3. `bash.exe` on PATH (Cygwin, MSYS2, WSL)
+
+For most users, [Git for Windows](https://git-scm.com/download/win) is sufficient.
+
+## Custom Shell Path
+
+```json
+{
+  "shellPath": "C:\\cygwin64\\bin\\bash.exe"
+}
+```