feat(auth): guest login with random telegraph operator name

No email required — players pick male/female/mystery, get assigned
a humorous period-appropriate operator name (e.g. "Dusty Clicksworth",
"Ada Dottsworth", "The Phantom Sender"), can reroll, then hit
"Begin Transmitting!" for instant play. Email/magic link moved to
a collapsible section for cross-device access only.

- server: POST /api/auth/guest creates guest profile + session
- server/db: profiles.email now nullable, is_guest column added,
  migration recreates table for existing installs
- client: names.ts with 15 names per gender category
- client: LoginPage redesigned — gender picker → name display → play
- client: useAuth gains setAuth() for direct session injection
- 55 server + 44 client tests pass

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

client/src/lib/names.ts

@@ -0,0 +1,60 @@
+export type Gender = 'male' | 'female' | 'mystery'
+
+export const OPERATOR_NAMES: Record<Gender, string[]> = {
+  male: [
+    'Dusty Clicksworth',
+    'Buck Dittley',
+    'Flash Henderson',
+    'Smokey McBeep',
+    'Knuckles McGee',
+    'Leadfoot Larry Tapsworth',
+    'Jittery Jack Clicker',
+    "Two-Finger Tex",
+    'Wild Bill Keyer',
+    'Rusty Tapper',
+    'Cactus Pete Signalton',
+    'Ol\' Sparky Johnson',
+    'Slick Fingersby',
+    'Gabby Dan Dashmore',
+    'Young Buck Beepsworth',
+  ],
+  female: [
+    'Ada Dottsworth',
+    'Clementine Dashford',
+    'Pearl Signalton',
+    'Nellie Tapsworth',
+    'Hattie Clickmore',
+    'Violet Waverley',
+    'Mabel Keymoor',
+    'Belle Dashmore',
+    'Ruby Signalbright',
+    'Clara Quick-Keys',
+    'Ethel Clicksworth',
+    'Dot O\'Dashes',
+    'Hazel Transmitter',
+    'Iris Tapford',
+    'Goldie Wavemore',
+  ],
+  mystery: [
+    'The Phantom Sender',
+    'Agent Dot-Dash',
+    'X. Marconi',
+    'The Ghost Operator',
+    'Shadow Keyer',
+    'The Unknown Transmitter',
+    'Agent Zero-Zero',
+    'The Masked Tapper',
+    'Signal Unknown',
+    'The Wandering Wave',
+    'Cipher McGee',
+    'The Midnight Sender',
+    'Static McFrequency',
+    'Professor Dash',
+    'The Lone Transmitter',
+  ],
+}
+
+export function randomName(gender: Gender): string {
+  const list = OPERATOR_NAMES[gender]
+  return list[Math.floor(Math.random() * list.length)]
+}