feat(workspace): add full-text search for daily memory files

Add backend search command that performs case-insensitive matching
across all daily memory files, supporting both date and content queries.
Frontend includes animated search bar (⌘F), debounced input, snippet
display with match count badge, and search state preservation across
edits.

src-tauri/src/commands/workspace.rs

@@ -147,6 +147,141 @@ pub async fn write_daily_memory_file(filename: String, content: String) -> Resul
         .map_err(|e| format!("Failed to write daily memory file {filename}: {e}"))
 }
 
+/// Find the largest index `<= i` that is a valid UTF-8 char boundary.
+/// Equivalent to the unstable `str::floor_char_boundary` (stabilized in 1.91).
+fn floor_char_boundary(s: &str, mut i: usize) -> usize {
+    if i >= s.len() {
+        return s.len();
+    }
+    while !s.is_char_boundary(i) {
+        i -= 1;
+    }
+    i
+}
+
+/// Find the smallest index `>= i` that is a valid UTF-8 char boundary.
+/// Equivalent to the unstable `str::ceil_char_boundary` (stabilized in 1.91).
+fn ceil_char_boundary(s: &str, mut i: usize) -> usize {
+    if i >= s.len() {
+        return s.len();
+    }
+    while !s.is_char_boundary(i) {
+        i += 1;
+    }
+    i
+}
+
+/// Search result for daily memory full-text search.
+#[derive(serde::Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct DailyMemorySearchResult {
+    pub filename: String,
+    pub date: String,
+    pub size_bytes: u64,
+    pub modified_at: u64,
+    pub snippet: String,
+    pub match_count: usize,
+}
+
+/// Full-text search across all daily memory files.
+///
+/// Performs case-insensitive search on both the date field and file content.
+/// Returns results sorted by filename descending (newest first), each with a
+/// snippet showing ~120 characters of context around the first match.
+#[tauri::command]
+pub async fn search_daily_memory_files(
+    query: String,
+) -> Result<Vec<DailyMemorySearchResult>, String> {
+    let memory_dir = get_openclaw_dir().join("workspace").join("memory");
+
+    if !memory_dir.exists() || query.is_empty() {
+        return Ok(Vec::new());
+    }
+
+    let query_lower = query.to_lowercase();
+    let mut results: Vec<DailyMemorySearchResult> = Vec::new();
+
+    let entries = std::fs::read_dir(&memory_dir)
+        .map_err(|e| format!("Failed to read memory directory: {e}"))?;
+
+    for entry in entries.flatten() {
+        let name = entry.file_name().to_string_lossy().to_string();
+        if !name.ends_with(".md") {
+            continue;
+        }
+        let meta = match entry.metadata() {
+            Ok(m) if m.is_file() => m,
+            _ => continue,
+        };
+
+        let date = name.trim_end_matches(".md").to_string();
+        let content = std::fs::read_to_string(entry.path()).unwrap_or_default();
+        let content_lower = content.to_lowercase();
+
+        // Count matches in content
+        let content_matches: Vec<usize> = content_lower
+            .match_indices(&query_lower)
+            .map(|(i, _)| i)
+            .collect();
+
+        // Also check date field
+        let date_matches = date.to_lowercase().contains(&query_lower);
+
+        if content_matches.is_empty() && !date_matches {
+            continue;
+        }
+
+        // Build snippet around first content match (~120 chars of context)
+        let snippet = if let Some(&first_pos) = content_matches.first() {
+            let start = if first_pos > 50 {
+                floor_char_boundary(&content, first_pos - 50)
+            } else {
+                0
+            };
+            let end = ceil_char_boundary(&content, (first_pos + 70).min(content.len()));
+            let mut s = String::new();
+            if start > 0 {
+                s.push_str("...");
+            }
+            s.push_str(&content[start..end]);
+            if end < content.len() {
+                s.push_str("...");
+            }
+            s
+        } else {
+            // Date-only match — use beginning of file as preview
+            let end = ceil_char_boundary(&content, 120.min(content.len()));
+            let mut s = content[..end].to_string();
+            if end < content.len() {
+                s.push_str("...");
+            }
+            s
+        };
+
+        let size_bytes = meta.len();
+        let modified_at = meta
+            .modified()
+            .ok()
+            .and_then(|t| t.duration_since(std::time::UNIX_EPOCH).ok())
+            .map(|d| d.as_secs())
+            .unwrap_or(0);
+
+        results.push(DailyMemorySearchResult {
+            filename: name,
+            date,
+            size_bytes,
+            modified_at,
+            snippet,
+            match_count: content_matches.len(),
+        });
+    }
+
+    // Sort by filename descending (newest date first)
+    results.sort_by(|a, b| b.filename.cmp(&a.filename));
+
+    Ok(results)
+}
+
 /// Delete a daily memory file (idempotent).
 #[tauri::command]
 pub async fn delete_daily_memory_file(filename: String) -> Result<(), String> {

src-tauri/src/lib.rs

@@ -1051,6 +1051,7 @@ pub fn run() {
             commands::read_daily_memory_file,
             commands::write_daily_memory_file,
             commands::delete_daily_memory_file,
+            commands::search_daily_memory_files,
         ]);
 
     let app = builder