feat: editor improvements and architectural grid prototype

Multiple feature additions and improvements across the application:

- NextGen Editor: drag handles, smart paste, block actions
- Structured views: Kanban and table layouts for notes
- Architectural Grid: new brainstorming/agent interface prototype
- Flashcards: SM-2 revision algorithm with AI generation
- MCP server: robustness improvements
- Graph/PDF chat: fix click propagation and copy behavior
- Various UI/UX enhancements and bug fixes

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memento-note/locales/en.json

@@ -74,7 +74,10 @@
     "noReminders": "No active reminders.",
     "documents": "Documents",
     "searchNotebooksPlaceholder": "Search notebooks…",
-    "clearSearch": "Clear search"
+    "clearSearch": "Clear search",
+    "insightsPanelBody": "Semantic map of your notes: thematic clusters, bridge notes, and connection suggestions.",
+    "revisionPanelBody": "Review flashcards with the SM-2 algorithm. Decks are generated from your notes.",
+    "backToNotebooks": "Back to notebooks"
   },
   "notes": {
     "title": "Notes",
@@ -2347,6 +2350,8 @@
     "slashDividerDesc": "Horizontal separator",
     "slashTable": "Table",
     "slashTableDesc": "Insert a simple grid",
+    "slashDatabase": "Database",
+    "slashDatabaseDesc": "Inline authors & works database",
     "slashDiagram": "Diagram",
     "slashDiagramDesc": "Generate a flow or mindmap",
     "slashSlides": "Presentation",
@@ -3310,5 +3315,76 @@
     "uploadError": "Upload error",
     "uploadFailed": "Upload failed",
     "uploading": "Uploading..."
+  },
+  "blockAction": {
+    "delete": "Delete",
+    "duplicate": "Duplicate",
+    "turnInto": "Turn into",
+    "turnInto_heading1": "Heading 1",
+    "turnInto_heading2": "Heading 2",
+    "turnInto_heading3": "Heading 3",
+    "turnInto_bulletList": "Bullet List",
+    "turnInto_orderedList": "Numbered List",
+    "turnInto_taskList": "Task List",
+    "turnInto_blockquote": "Quote",
+    "turnInto_codeBlock": "Code Block",
+    "turnInto_database": "Database",
+    "copyRef": "Copy block reference",
+    "copied": "Reference copied!",
+    "copyRefFailed": "Could not copy block reference",
+    "copyRefNoNote": "Save the note before copying a block reference",
+    "copyRefUnsupported": "This block type cannot be referenced yet"
+  },
+  "smartPaste": {
+    "prompt": "Paste this block reference as:",
+    "liveBlock": "Connected block (live)",
+    "plainLink": "Plain text / link",
+    "unknownNote": "Untitled note"
+  },
+  "liveBlock": {
+    "connectedNote": "Connected note",
+    "sourceDisconnected": "Source disconnected",
+    "statusLive": "LIVE",
+    "statusOffline": "OFFLINE",
+    "statusDisconnected": "DISCONNECTED",
+    "detachLink": "Unlink block",
+    "detachHelp": "Convert this block to normal text in this note",
+    "openSource": "Open",
+    "removeBlock": "Remove block",
+    "emptyContent": "(empty block)"
+  },
+  "notePeek": {
+    "label": "Linked note",
+    "panelLabel": "Source note preview",
+    "close": "Close preview",
+    "openFully": "Open full screen",
+    "openFullyHelp": "Replace the current note with this one",
+    "readOnlyHint": "Read-only preview — open full screen to edit.",
+    "loadFailed": "Could not open the linked note preview."
+  },
+  "databaseBlock": {
+    "title": "Authors & Works",
+    "hint": "Inline database — data is stored in this note.",
+    "viewTable": "Table",
+    "viewCards": "Cards",
+    "colAuthor": "Author",
+    "colWorks": "Works",
+    "colRollup": "Rollup",
+    "noLinkedWorks": "No linked works",
+    "deleteShort": "Del",
+    "deleteCard": "Remove work",
+    "addAuthor": "Add author",
+    "authorPlaceholder": "Author name…",
+    "createAuthor": "Create",
+    "addWork": "Add a work",
+    "bookTitlePlaceholder": "Work title…",
+    "selectAuthor": "Select author…",
+    "tagPlaceholder": "Genre / tag…",
+    "coverPlaceholder": "Cover image URL (optional)",
+    "insertWork": "Insert work",
+    "defaultTag": "General",
+    "worksBase": "Works database",
+    "storedCount": "{count} work(s) stored",
+    "insertFailed": "Could not insert the database block. Try again on an empty line."
   }
 }