fixing some claude-isms

crates/weaver-app/src/components/editor/document.rs

···
 impl EditorDocument {
     /// Check if a character position is within the block-syntax zone of its line.
     fn is_in_block_syntax_zone(&self, pos: usize) -> bool {
-        if pos == 0 {
+        if pos <= BLOCK_SYNTAX_ZONE {
             return true;
         }
 
-        let content_str = self.content.to_string();
-        let mut last_newline_pos: Option<usize> = None;
-
-        for (i, c) in content_str.chars().take(pos).enumerate() {
-            if c == '\n' {
-                last_newline_pos = Some(i);
+        // Search backwards from pos-1, only need to check BLOCK_SYNTAX_ZONE + 1 chars.
+        let search_start = pos.saturating_sub(BLOCK_SYNTAX_ZONE + 1);
+        for i in (search_start..pos).rev() {
+            if self.content.char_at(i).ok() == Some('\n') {
+                // Found newline at i, distance from line start is pos - i - 1.
+                return (pos - i - 1) <= BLOCK_SYNTAX_ZONE;
             }
         }
-
-        let chars_from_line_start = match last_newline_pos {
-            Some(nl_pos) => pos - nl_pos - 1,
-            None => pos,
-        };
-
-        chars_from_line_start <= BLOCK_SYNTAX_ZONE
+        // No newline found in search range, and pos > BLOCK_SYNTAX_ZONE, so not in zone.
+        false
     }
 
     /// Create a new editor document with the given content.
···
 
     /// Remove text range from content and record edit info for incremental rendering.
     pub fn remove_tracked(&mut self, start: usize, len: usize) -> LoroResult<()> {
-        let content_str = self.content.to_string();
-        let contains_newline = content_str.chars().skip(start).take(len).any(|c| c == '\n');
+        let contains_newline = self
+            .content
+            .slice(start, start + len)
+            .map(|s| s.contains('\n'))
+            .unwrap_or(false);
         let in_block_syntax_zone = self.is_in_block_syntax_zone(start);
 
         let result = self.content.delete(start, len);
···
 
     /// Replace text in content (delete then insert) and record combined edit info.
     pub fn replace_tracked(&mut self, start: usize, len: usize, text: &str) -> LoroResult<()> {
-        let content_str = self.content.to_string();
-        let delete_has_newline = content_str.chars().skip(start).take(len).any(|c| c == '\n');
+        let delete_has_newline = self
+            .content
+            .slice(start, start + len)
+            .map(|s| s.contains('\n'))
+            .unwrap_or(false);
         let in_block_syntax_zone = self.is_in_block_syntax_zone(start);
 
         let len_before = self.content.len_unicode();

crates/weaver-editor-crdt/src/buffer.rs

···
 use std::ops::Range;
 use std::rc::Rc;
 
-use loro::{LoroDoc, LoroText, UndoManager as LoroUndoManager, VersionVector};
+use loro::{cursor::PosType, LoroDoc, LoroText, UndoManager as LoroUndoManager, VersionVector};
 use smol_str::{SmolStr, ToSmolStr};
 use weaver_editor_core::{TextBuffer, UndoManager};
 
···
 
 impl TextBuffer for LoroTextBuffer {
     fn len_bytes(&self) -> usize {
-        self.content.to_string().len()
+        self.content.len_utf8()
     }
 
     fn len_chars(&self) -> usize {
···
     }
 
     fn slice(&self, char_range: Range<usize>) -> Option<SmolStr> {
-        let s = self.content.to_string();
-        let chars: Vec<char> = s.chars().collect();
-
-        if char_range.end > chars.len() {
+        if char_range.end > self.content.len_unicode() {
             return None;
         }
-
-        let slice: String = chars[char_range].iter().collect();
-        Some(slice.to_smolstr())
+        self.content
+            .slice(char_range.start, char_range.end)
+            .ok()
+            .map(|s| s.to_smolstr())
     }
 
     fn char_at(&self, char_offset: usize) -> Option<char> {
-        let s = self.content.to_string();
-        s.chars().nth(char_offset)
+        self.content.char_at(char_offset).ok()
     }
 
     fn to_string(&self) -> String {
···
     }
 
     fn char_to_byte(&self, char_offset: usize) -> usize {
-        let s = self.content.to_string();
-        s.char_indices()
-            .nth(char_offset)
-            .map(|(i, _)| i)
-            .unwrap_or(s.len())
+        self.content
+            .convert_pos(char_offset, PosType::Unicode, PosType::Bytes)
+            .unwrap_or(self.content.len_utf8())
     }
 
     fn byte_to_char(&self, byte_offset: usize) -> usize {
-        let s = self.content.to_string();
-        s[..byte_offset.min(s.len())].chars().count()
+        self.content
+            .convert_pos(byte_offset, PosType::Bytes, PosType::Unicode)
+            .unwrap_or(self.content.len_unicode())
     }
 }
 

docs/graph-data.json

···
       "created_at": "2026-01-06T14:36:23.710415853-05:00",
       "updated_at": "2026-01-06T14:36:23.710415853-05:00",
       "metadata_json": "{\"confidence\":95}"
+    },
+    {
+      "id": 157,
+      "change_id": "e1666f70-0b8a-4a9e-9716-bd550899e65c",
+      "node_type": "action",
+      "title": "Moved fetch_blob to WeaverExt trait in weaver-common",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T15:16:33.868867777-05:00",
+      "updated_at": "2026-01-06T15:16:33.868867777-05:00",
+      "metadata_json": "{\"confidence\":95}"
+    },
+    {
+      "id": 158,
+      "change_id": "89ef84b5-0909-4367-8644-4392c1cf4c3a",
+      "node_type": "action",
+      "title": "Added use-index cfg gates to crdt sync functions (find_all_edit_roots, list_drafts)",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T15:16:33.886464900-05:00",
+      "updated_at": "2026-01-06T15:16:33.886464900-05:00",
+      "metadata_json": "{\"confidence\":95}"
+    },
+    {
+      "id": 159,
+      "change_id": "f3f310fb-78e3-4178-98a3-20d55e20c85a",
+      "node_type": "action",
+      "title": "Refactored app sync.rs - removed ~1100 lines of duplicated code, re-exports crdt types",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T15:16:33.904856197-05:00",
+      "updated_at": "2026-01-06T15:16:33.904856197-05:00",
+      "metadata_json": "{\"confidence\":95}"
+    },
+    {
+      "id": 160,
+      "change_id": "da49b35a-6ca3-4d59-a1f8-84f359693565",
+      "node_type": "outcome",
+      "title": "Sync extraction complete - app sync.rs now thin wrapper over weaver-editor-crdt, both use-index and non-use-index paths compile",
+      "description": null,
+      "status": "pending",
+      "created_at": "2026-01-06T15:16:33.936978250-05:00",
+      "updated_at": "2026-01-06T15:16:33.936978250-05:00",
+      "metadata_json": "{\"confidence\":95}"
     }
   ],
   "edges": [
···
       "weight": 1.0,
       "rationale": "Completed fix",
       "created_at": "2026-01-06T14:36:23.726201054-05:00"
+    },
+    {
+      "id": 163,
+      "from_node_id": 153,
+      "to_node_id": 157,
+      "from_change_id": "f357a30f-0000-4b09-bb35-fe6c23b1dccf",
+      "to_change_id": "e1666f70-0b8a-4a9e-9716-bd550899e65c",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "fetch_blob needed for crdt sync to work standalone",
+      "created_at": "2026-01-06T15:16:39.378273071-05:00"
+    },
+    {
+      "id": 164,
+      "from_node_id": 157,
+      "to_node_id": 158,
+      "from_change_id": "e1666f70-0b8a-4a9e-9716-bd550899e65c",
+      "to_change_id": "89ef84b5-0909-4367-8644-4392c1cf4c3a",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "cfg gates next step after fetch_blob available",
+      "created_at": "2026-01-06T15:16:39.394339283-05:00"
+    },
+    {
+      "id": 165,
+      "from_node_id": 158,
+      "to_node_id": 159,
+      "from_change_id": "89ef84b5-0909-4367-8644-4392c1cf4c3a",
+      "to_change_id": "f3f310fb-78e3-4178-98a3-20d55e20c85a",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "app sync.rs refactor follows crdt having both paths",
+      "created_at": "2026-01-06T15:16:39.410629272-05:00"
+    },
+    {
+      "id": 166,
+      "from_node_id": 159,
+      "to_node_id": 160,
+      "from_change_id": "f3f310fb-78e3-4178-98a3-20d55e20c85a",
+      "to_change_id": "da49b35a-6ca3-4d59-a1f8-84f359693565",
+      "edge_type": "leads_to",
+      "weight": 1.0,
+      "rationale": "refactor completed successfully",
+      "created_at": "2026-01-06T15:16:39.426610084-05:00"
     }
   ]
 }