Passphrases and E.164: June hardening

Security and correctness work, each backed by a written decision record. SIP endpoint passwords now auto-generate as five-word passphrases (roughly 56 bits of entropy): strong enough to trust, readable enough to type into a desk phone’s keypad.

Inbound DID matching tolerates the optional plus sign that carriers add or drop at will, and caller IDs normalize to E.164 before partner lookup, so a call from 0313808316 finds the contact saved as +41313808316. Small rules, fewer mystery “unknown caller” records.