fix: Radix UI Select empty value crash in deal form

Issue: Deal form crashed when opening contact dropdown
Root Cause: Radix UI Select doesn't support empty string values
Solution: Use sentinel value "__none__" instead of empty string

Changes:
- src/modules/deals/components/deal-form.tsx
  * Line 133: Updated onValueChange to handle "__none__" sentinel
  * Line 136: Set default value to "__none__" when contactId is undefined
  * Line 144: Changed SelectItem value from "" to "__none__"

- SESSION.md
  * Added "Post-Launch Bug Fixes" section
  * Documented bug fix details

Tested: Deal form now opens without errors, "None" option works correctly

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: Jez

SESSION.md

@@ -1,8 +1,8 @@
 # Session State
 
-**Current Phase**: Phase 6
-**Current Stage**: Planning
-**Last Checkpoint**: 3950032 (2025-11-08)
+**Current Phase**: All phases complete! 🎉
+**Current Stage**: Production Ready
+**Last Checkpoint**: df75e37 (2025-11-08)
 **Planning Docs**: `docs/IMPLEMENTATION_PHASES.md`, `docs/DATABASE_SCHEMA.md`
 
 ---
@@ -68,7 +68,7 @@
 - `src/components/navigation.tsx` (changed title from "TodoApp" to "CRM")
 
 ## Phase 6: Testing & Documentation ✅
-**Completed**: 2025-11-08 | **Checkpoint**: (pending)
+**Completed**: 2025-11-08 | **Checkpoint**: df75e37
 **Summary**: Created comprehensive testing and documentation suite. Added seed script with realistic data (10 contacts, 5 tags, 5 deals), complete testing checklist (TESTING.md), verified DATABASE_SCHEMA.md accuracy, and updated README.md with CRM features section.
 
 **Key Deliverables**:
@@ -92,3 +92,14 @@
 - Database schema with ERD and query patterns
 - Testing checklist with manual test procedures
 - README with CRM features overview and module structure
+
+---
+
+## Post-Launch Bug Fixes
+
+### Bug Fix: Radix UI Select Empty Value (2025-11-08)
+**Issue**: Deal form crashed when opening contact dropdown due to empty string value in SelectItem
+**Root Cause**: Radix UI Select doesn't support empty string values
+**Fix**: Replaced `value=""` with sentinel value `"__none__"` and updated onChange logic
+**File**: `src/modules/deals/components/deal-form.tsx` (lines 133, 136, 144)
+**Status**: ✅ Fixed and tested

src/modules/deals/components/deal-form.tsx

@@ -130,18 +130,18 @@ export function DealForm({ initialData, contacts }: DealFormProps) {
                                     <Select
                                         onValueChange={(value) =>
                                             field.onChange(
-                                                value ? Number.parseInt(value) : undefined,
+                                                value === "__none__" ? undefined : Number.parseInt(value),
                                             )
                                         }
-                                        value={field.value?.toString()}
+                                        value={field.value?.toString() || "__none__"}
                                     >
                                         <FormControl>
                                             <SelectTrigger>
                                                 <SelectValue placeholder="Select a contact" />
                                             </SelectTrigger>
                                         </FormControl>
                                         <SelectContent>
-                                            <SelectItem value="">None</SelectItem>
+                                            <SelectItem value="__none__">None</SelectItem>
                                             {contacts.map((contact) => (
                                                 <SelectItem
                                                     key={contact.id}