Pairing: scan a QR off the terminal once; the cookie lasts a year

The key already persisted across restarts, but the cookie was a
session cookie — Safari eventually drops those and the paste ritual
returned. The pairing cookie now lasts a year, and startup prints a QR
code of the pairing URL (qrcode dep, ASCII render) so a phone pairs by
pointing its camera at the terminal. Revoke every paired device by
deleting data/.lan_key.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jXZFSTZQKzAC8fqpWSz9g

uv.lock

@@ -65,6 +65,7 @@ dependencies = [
     { name = "playwright" },
     { name = "pydantic" },
     { name = "python-multipart" },
+    { name = "qrcode" },
     { name = "rapidfuzz" },
     { name = "rich" },
     { name = "typer" },
@@ -88,6 +89,7 @@ requires-dist = [
     { name = "playwright", specifier = ">=1.62.0" },
     { name = "pydantic", specifier = ">=2.13.4" },
     { name = "python-multipart", specifier = ">=0.0.32" },
+    { name = "qrcode", specifier = ">=8.2" },
     { name = "rapidfuzz", specifier = ">=3.9" },
     { name = "rich", specifier = ">=15.0.0" },
     { name = "typer", specifier = ">=0.12" },
@@ -671,6 +673,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/e1/04/e8135ebd1ad02c56ec633277529b2602ff99ff634be76cdba5744cf554fd/python_multipart-0.0.32-py3-none-any.whl", hash = "sha256:ff6d3f776f16878c894e52e107296ffc890e913c611b1a4ec6c44e2821fe2e23", size = 30042, upload-time = "2026-06-04T16:18:57.319Z" },
 ]
 
+[[package]]
+name = "qrcode"
+version = "8.2"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "colorama", marker = "sys_platform == 'win32'" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/8f/b2/7fc2931bfae0af02d5f53b174e9cf701adbb35f39d69c2af63d4a39f81a9/qrcode-8.2.tar.gz", hash = "sha256:35c3f2a4172b33136ab9f6b3ef1c00260dd2f66f858f24d88418a015f446506c", size = 43317, upload-time = "2025-05-01T15:44:24.726Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/dd/b8/d2d6d731733f51684bbf76bf34dab3b70a9148e8f2cef2bb544fccec681a/qrcode-8.2-py3-none-any.whl", hash = "sha256:16e64e0716c14960108e85d853062c9e8bba5ca8252c0b4d0231b9df4060ff4f", size = 45986, upload-time = "2025-05-01T15:44:22.781Z" },
+]
+
 [[package]]
 name = "rapidfuzz"
 version = "3.14.5"