v1: cleanup, dead code removal, docs update

app.py:
- Move warnings import to top-level imports
- Remove MICRONAS_SECRET env var (undocumented, unnecessary)
- Inline secret key derivation cleanly

CLAUDE.md:
- Remove stale quotas mention
- Add WebDAV, setup.html, favicon to file layout
- Document /etc/micronas/ permissions requirements
- Document <Location> vs <Directory> for WebDAV DAV On

PLANNING.md:
- Mark Phase 5 complete with all shipped items
- Add v1 complete marker and future ideas section

README.md:
- Simplify dev/test section (remove complex hash snippet)
- Fix double blank line

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -85,18 +85,11 @@ LAN or Tailscale only — never expose to the internet.
 ## Dev / test
 
 ```bash
-# Quick local run (no gunicorn needed, must have flask installed):
-MICRONAS_USER=admin MICRONAS_PASS_HASH="$(python3 -c "
-import hashlib, os
-s=os.urandom(16).hex()
-h=hashlib.pbkdf2_hmac('sha256',b'secret',s.encode(),260000).hex()
-print(f'{s}\${h}')
-")" flask --app app.py run --debug --host=0.0.0.0
+# Plaintext password — dev only, not for production
+MICRONAS_USER=admin MICRONAS_PASS=secret flask --app app.py run --debug --host=0.0.0.0
 ```
 
-Or use plaintext for dev only (still supported): `MICRONAS_USER=admin MICRONAS_PASS=secret flask --app app.py run --debug`
-
-Note: SMB/NFS/user management calls require root and the relevant daemons — run on the actual LXC for full testing.
+SMB/NFS/user management requires root and the actual daemons — test on the LXC.
 
 ## Auth
 
@@ -104,7 +97,6 @@ All routes require a login session. On first run you are redirected to `/setup`
 
 **Changing the admin password** — click the ⚙ Settings button in the top-right corner. Enter your current password to confirm, then set a new username and/or password. You will be logged out automatically and redirected to login.
 
-
 ---
 
 ## User management