Fix mobile camera fallback and scanner theme

public/theme.css

@@ -26,6 +26,7 @@ th{background:var(--surface-table);color:var(--muted-2)}th,td,.records nav,.back
 .customer-notes article,.backup-list,.user-list,.model-list,.warranty-list,.audit-list{border-color:var(--border)}
 .model-list article{border-color:var(--border)}.model-summary small{color:var(--muted)}.model-status.active{background:var(--green-soft);color:var(--green)}.model-status.archived{background:var(--surface-soft);color:var(--muted)}
 .warranty-list article,.conditional-fields,.sale-items,.sale-item{border-color:var(--border)}.conditional-fields,.sale-summary{background:var(--surface-soft)}.sale-item small,.sale-summary span,.conditional-hint{color:var(--muted)}.conditional-hint{border-color:var(--border-strong)}.field-help{color:var(--muted)}.warranty-pill.in-warranty{background:var(--green-soft);color:var(--green)}.warranty-pill.expired{background:var(--danger-soft);color:var(--danger)}.warranty-pill.neutral{background:var(--surface-soft);color:var(--muted)}
+.scan-panel,.scanner-overlay,.scanner-overlay input,.scanner-overlay select,.scanner-overlay textarea{color:var(--text)}.scan-panel{background:var(--surface-soft);border-color:var(--border)}.scan-panel input,.scan-panel select,.scan-panel textarea{background:var(--surface);border-color:var(--border-strong);color:var(--text)}.scanner-overlay{background:#000c}.scanner-overlay>div{background:var(--surface);color:var(--text);border:1px solid var(--border)}.scanner-overlay button{background:var(--blue);color:#fff}
 .filter-bar{border-color:var(--border);background:var(--surface-soft)}.filter-bar .button{background:var(--surface);border:1px solid var(--border-strong);color:var(--text)}.customer-match{color:var(--blue-text)!important}.diagnostic-grid article,.automatic-backups{background:var(--surface-soft);border-color:var(--border)}.diagnostic-grid span,.diagnostic-grid small,.automatic-backups p,.backup-schedule-status{color:var(--muted)}.export-links .button{background:var(--surface-soft);border:1px solid var(--border-strong);color:var(--text)}
 .note-category{background:var(--blue-soft);color:var(--blue-text)}.backup-warning{background:var(--warning-soft);border-color:color-mix(in srgb,var(--warning) 40%,transparent);color:var(--warning)}
 .auth-screen{background:linear-gradient(145deg,color-mix(in srgb,var(--blue) 10%,var(--page)),var(--page))}.auth-card{box-shadow:0 22px 60px var(--shadow)}