feat: legibility — conditions, hints, kinder errors (Workstream B)

GET /api/conditions surfaces what the backend already computes: moon
phase, veil thinness, geomagnetic state — junk lon degrades to moon-only
instead of a 422, missing NOAA data means fewer lines, never an error.
VeilConditions renders it in the séance side column, polling every 10 min.

ModeHint: one in-fiction line per mode after 15s of an unused sensor,
dismissed forever via localStorage. Error copy in evp/radio now
detect-and-redirects (mic denied -> 'the board needs no ear'; no WebUSB
-> try EVP) instead of dead-ending.

No geolocation prompt from the conditions strip — asking for location
from a passive readout would be hostile; ?lon= stays supported for
callers that have it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

# Conflicts:
#	frontend/src/pages/SeancePage.tsx

frontend/src/pages/SeancePage.tsx

@@ -27,6 +27,8 @@ import { RitualPanel } from '../components/RitualPanel'
 import { DeviceWhisper } from '../components/DeviceWhisper'
 import { JudgmentPanel } from '../components/JudgmentPanel'
 import { TelemetryReadout } from '../components/TelemetryReadout'
+import { VeilConditions } from '../components/VeilConditions'
+import { ModeHint } from '../components/ModeHint'
 import { PlanchetteMachine } from '../lib/planchette'
 import type { PlanchetteSnapshot } from '../lib/planchette'
 import { EvpListener } from '../lib/evp'
@@ -387,6 +389,7 @@ function SeanceSession({ username }: { username: string }) {
             onToggleOpen={() => setDossierOpen((o) => !o)}
           />
 
+          <VeilConditions />
           <DeviceWhisper />
           <RitualPanel />
           <JudgmentPanel />
@@ -503,6 +506,7 @@ function WirePanel() {
           })}
         </p>
       )}
+      <ModeHint mode="wire" suppressed={state.passive} />
     </div>
   )
 }
@@ -666,6 +670,7 @@ function EvpPanel() {
       >
         {listening ? t('seance.evp.stop') : t('seance.evp.start')}
       </button>
+      <ModeHint mode="evp" suppressed={listening || pending} />
     </div>
   )
 }
@@ -895,6 +900,7 @@ function RadioPanel() {
       >
         {phase === 'sweeping' ? t('seance.radio.stop') : t('seance.radio.start')}
       </button>
+      <ModeHint mode="radio" suppressed={phase !== 'idle'} />
     </div>
   )
 }
@@ -935,6 +941,7 @@ function OuijaPanel({ snapshot }: { snapshot: PlanchetteSnapshot | null }) {
       {snapshot && snapshot.spelled.length > 0 && (
         <p className="ouija-history dim">{snapshot.spelled.slice(-6).join(' · ')}</p>
       )}
+      <ModeHint mode="ouija" suppressed={word !== null} />
     </div>
   )
 }
@@ -1193,6 +1200,7 @@ function EmfPanel() {
           {t('seance.emf.calibrate', { defaultValue: 'calibrate' })}
         </button>
       </div>
+      <ModeHint mode="emf" suppressed={listening || pending} />
     </div>
   )
 }