feat: Implement node deletion with shared modal and fix SurrealDB RecordId handling

Implements complete node deletion functionality for both galaxy view and debug panel:

**Core Changes:**
- Created shared DeleteNodeModal component used by both ThoughtGalaxy and UserMenu
- Modal provides consistent UX with proper confirmation messaging
- Deletion follows write-through cache pattern: ATproto first, then SurrealDB

**SurrealDB RecordId Fixes:**
- Fixed SELECT query to use type::thing($table, $recordId) for UUID-based RecordIds
- Fixed DELETE query to use type::thing() instead of db.delete() to handle dashes in UUIDs
- Without type::thing(), SurrealDB interprets dashes as subtraction operators

**Testing & Documentation:**
- Added comprehensive Magnitude tests for delete functionality (galaxy view and debug panel)
- Updated CLAUDE.md with complete testing workflow documentation
- Added pre-commit checklist requiring database verification and test execution
- Documented PlaywrightMCP manual testing process before Magnitude test writing

**Database Setup:**
- Configured docker-compose.yml to use environment variables for credentials
- Updated namespace/database to match .env configuration (ponderants/main)

**File Changes:**
- app/api/nodes/[id]/route.ts: Fixed RecordId query patterns (SELECT and DELETE)
- components/DeleteNodeModal.tsx: New shared modal component
- components/ThoughtGalaxy.tsx: Uses shared DeleteNodeModal
- components/UserMenu.tsx: Replaced browser confirm() with shared DeleteNodeModal
- tests/magnitude/03-delete-node.mag.ts: Added debug panel delete test
- AGENTS.md: Added testing workflow and pre-commit checklist documentation
- docker-compose.yml: Environment variable configuration

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

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

components/ThoughtGalaxy.tsx

@@ -7,9 +7,10 @@ import {
   Text,
 } from '@react-three/drei';
 import { Suspense, useEffect, useRef, useState } from 'react';
-import { Stack, Text as MantineText, Paper, Title, Box, CloseButton, Group, Anchor, useComputedColorScheme, Button, Modal } from '@mantine/core';
+import { Stack, Text as MantineText, Paper, Title, Box, CloseButton, Group, Anchor, useComputedColorScheme, Button } from '@mantine/core';
 import { IconTrash } from '@tabler/icons-react';
 import { notifications } from '@mantine/notifications';
+import { DeleteNodeModal } from './DeleteNodeModal';
 import { useRouter, usePathname, useSearchParams } from 'next/navigation';
 import * as THREE from 'three';
 
@@ -482,41 +483,13 @@ export function ThoughtGalaxy() {
       )}
 
       {/* Delete confirmation modal */}
-      <Modal
+      <DeleteNodeModal
         opened={deleteConfirmOpen}
         onClose={() => setDeleteConfirmOpen(false)}
-        title="Delete Node"
-        centered
-        zIndex={1001}
-      >
-        <Stack gap="md">
-          <MantineText>
-            Are you sure you want to delete this node? This will:
-          </MantineText>
-          <Stack gap="xs" ml="md">
-            <MantineText size="sm">• Remove the post from Bluesky</MantineText>
-            <MantineText size="sm">• Delete the node from your galaxy</MantineText>
-            <MantineText size="sm" fw={600} c="red">This action cannot be undone.</MantineText>
-          </Stack>
-          <Group justify="flex-end" gap="sm">
-            <Button
-              variant="subtle"
-              onClick={() => setDeleteConfirmOpen(false)}
-              disabled={isDeleting}
-            >
-              Cancel
-            </Button>
-            <Button
-              color="red"
-              onClick={handleDeleteNode}
-              loading={isDeleting}
-              leftSection={<IconTrash size={16} />}
-            >
-              Delete Permanently
-            </Button>
-          </Group>
-        </Stack>
-      </Modal>
+        onConfirm={handleDeleteNode}
+        nodeTitle={selectedNode?.title || null}
+        isDeleting={isDeleting}
+      />
 
       <Canvas
         camera={{ position: [0, 5, 10], fov: 60 }}