docs: Stale passlib references after bcrypt 5.x migration

[mrveiss]

Problem

After removing passlib in #2669 (PR #2799), several documentation files still reference it:

• docs/DEPENDENCIES.md lines 74, 333, 365 — lists passlib[bcrypt]>=1.7.4 as a dependency
• docs/plans/2026-01-15-slm-startup-procedure-design.md line 134 — lists passlib
• autobot-slm-backend/ansible/playbooks/enroll-node.yml line 41 — comment referencing from passlib.hash import sha512_crypt
• autobot-slm-backend/ansible/playbooks/enroll-local.yml line 27 — same passlib comment

Discovered During

Working on #2669 (bcrypt migration — Phase 1a)

Impact

Severity: low — documentation only, no runtime impact

Fix

• Update DEPENDENCIES.md to reference bcrypt>=5.0.0 instead of passlib
• Update Ansible comments to use python3 -c "import crypt; print(crypt.crypt('password'))" or mkpasswd
• Remove passlib from design doc dependency list

[github-actions]

PR #2930 (merged to Dev_new_gui) references this issue with a close keyword.

docs: remove stale passlib references after bcrypt 5.x migration (#2811)

If this issue is fully resolved, close it manually. If work remains, no action is needed.