feat: add icon and color fields to VaultEntry

- Add icon (string|null) and color (string|null) to VaultEntry interface
- Update Rust VaultEntry struct and frontmatter parsing to read icon/color
- Add icon/color to SKIP_KEYS so they don't appear as relationships
- Set mock data: Recipe type → cooking-pot/orange, Book type → book-open/green
- Update all test files with the new required fields

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/Editor.test.tsx

@@ -49,6 +49,8 @@ const mockEntry: VaultEntry = {
   fileSize: 1024,
   snippet: '',
   relationships: {},
+  icon: null,
+  color: null,
 }
 
 const mockContent = `---

src/components/Inspector.test.tsx

@@ -19,6 +19,8 @@ const mockEntry: VaultEntry = {
   fileSize: 1024,
   snippet: '',
   relationships: {},
+  icon: null,
+  color: null,
 }
 
 const mockContent = `---
@@ -54,6 +56,8 @@ const referrerEntry: VaultEntry = {
   fileSize: 200,
   snippet: '',
   relationships: {},
+  icon: null,
+  color: null,
 }
 
 const allContent: Record<string, string> = {

src/components/NoteList.test.tsx

@@ -25,6 +25,8 @@ const mockEntries: VaultEntry[] = [
     relationships: {
       'Related to': ['[[topic/software-development]]'],
     },
+    icon: null,
+    color: null,
   },
   {
     path: '/Users/luca/Laputa/note/facebook-ads-strategy.md',
@@ -45,6 +47,8 @@ const mockEntries: VaultEntry[] = [
       'Belongs to': ['[[project/26q1-laputa-app]]'],
       'Related to': ['[[topic/growth]]'],
     },
+    icon: null,
+    color: null,
   },
   {
     path: '/Users/luca/Laputa/person/matteo-cellini.md',
@@ -62,6 +66,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 320,
     snippet: 'Sponsorship manager.',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/Users/luca/Laputa/event/2026-02-14-kickoff.md',
@@ -79,6 +85,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 512,
     snippet: 'Project kickoff meeting notes.',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/Users/luca/Laputa/topic/software-development.md',
@@ -96,6 +104,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 256,
     snippet: 'Frontend, backend, and systems programming.',
     relationships: {},
+    icon: null,
+    color: null,
   },
 ]
 

src/components/Sidebar.test.tsx

@@ -20,6 +20,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 1024,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/responsibility/grow-newsletter.md',
@@ -37,6 +39,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 512,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/experiment/stock-screener.md',
@@ -54,6 +58,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 256,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/procedure/weekly-essays.md',
@@ -71,6 +77,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 128,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/topic/software-development.md',
@@ -88,6 +96,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 256,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/topic/trading.md',
@@ -105,6 +115,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 180,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/person/alice.md',
@@ -122,6 +134,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 100,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
   {
     path: '/vault/event/kickoff.md',
@@ -139,6 +153,8 @@ const mockEntries: VaultEntry[] = [
     fileSize: 200,
     snippet: '',
     relationships: {},
+    icon: null,
+    color: null,
   },
 ]
 
@@ -283,6 +299,8 @@ describe('Sidebar', () => {
         fileSize: 200,
         snippet: '',
         relationships: {},
+    icon: null,
+    color: null,
       },
       {
         path: '/vault/type/book.md',
@@ -300,6 +318,8 @@ describe('Sidebar', () => {
         fileSize: 200,
         snippet: '',
         relationships: {},
+    icon: null,
+    color: null,
       },
       {
         path: '/vault/recipe/pasta.md',
@@ -317,6 +337,8 @@ describe('Sidebar', () => {
         fileSize: 300,
         snippet: '',
         relationships: {},
+    icon: null,
+    color: null,
       },
     ]
 
@@ -362,6 +384,8 @@ describe('Sidebar', () => {
         fileSize: 200,
         snippet: '',
         relationships: {},
+    icon: null,
+    color: null,
       }
       render(<Sidebar entries={[...mockEntries, projectTypeEntry]} selection={defaultSelection} onSelect={() => {}} />)
       // "Projects" should appear once (the built-in section), not twice