fix: UI polish — nav labels, date picker, rules engine, error messages

- Sidebar: removed "Master" from nav labels (Leads, Patients, Appointments, Call Log)
- Appointment form: Dept + Doctor in 2-col row, Date below, disabled cascade
- DatePicker: placement="bottom start" + shouldFlip fixes popover positioning
- Team Performance: default to "Week", grid KPI cards, chart legend spacing
- Rules Engine: manual save (removed auto-debounce), Reset to Defaults uses
  DEFAULT_PRIORITY_CONFIG (no template endpoint), removed dead saveTimerRef
- Automation rules: 6 showcase cards with trigger/condition/action, replaced
  agent-specific rule with generic round-robin
- Recording analysis: friendly error message with retry instead of raw Deepgram error
- Sidebar active/hover: brand color reference for theming

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/application/date-picker/date-picker.tsx

@@ -40,7 +40,8 @@ export const DatePicker = ({ value: valueProp, defaultValue, onChange, onApply,
             </AriaGroup>
             <AriaPopover
                 offset={8}
-                placement="bottom right"
+                placement="bottom start"
+                shouldFlip
                 className={({ isEntering, isExiting }) =>
                     cx(
                         "origin-(--trigger-anchor-point) will-change-transform",