feat: status line helper scripts and setup documentation

Bash and PowerShell helpers for Claude Code statusLine. Setup docs with fallback note for non-Claude agents.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/status-line-setup.md

@@ -0,0 +1,65 @@
+# ctask Status Line Setup
+
+## Claude Code Integration
+
+ctask includes helper scripts that display task context in Claude Code's status line.
+
+### Setup
+
+Add one of the following to your `~/.claude/settings.json`:
+
+**Linux / macOS (bash):**
+
+```json
+{
+  "statusLine": {
+    "type": "command",
+    "command": "bash /path/to/ctask-statusline.sh"
+  }
+}
+```
+
+**Windows (PowerShell):**
+
+```json
+{
+  "statusLine": {
+    "type": "command",
+    "command": "powershell -NoProfile -File C:\\path\\to\\ctask-statusline.ps1"
+  }
+}
+```
+
+Replace `/path/to/` with the actual location of the script.
+
+### Output
+
+When inside a ctask session:
+
+```
+(ctask:arch-notes|local) ~/ai-workspaces/general/2026-04-05_arch-notes
+```
+
+When NOT in a ctask session: no output (falls through gracefully).
+
+### How It Works
+
+The scripts read only from environment variables set by ctask:
+
+- `CTASK_TASK` -- task slug
+- `CTASK_MODE` -- execution mode (local/container)
+- `CTASK_WORKSPACE` -- full workspace path
+
+No file parsing or subprocess calls are performed.
+
+## Non-Claude Agents
+
+For agents that do not support a dedicated status line, ctask provides an ephemeral
+shell prompt prefix in `--shell` mode:
+
+```
+(ctask:arch-notes|local) user@host:~/path$
+```
+
+This is set via `PS1` (Unix) or `PROMPT` (Windows) and does not modify permanent
+shell configuration.