feat: batch of fixes and features (#56)

## Summary

This PR includes a batch of bug fixes and new features:

### Bug Fixes
- **Links in chat history now open in default browser** instead of navigating within the app
  - Closes #54
- **Allow spaces in tab names** - space key no longer acts like enter when renaming tabs
  - Closes #52

### New Features
- **`/cd` command** - Change the working directory of an active tab with context preservation
  - Closes #55
- **`/search` command** - Search and highlight matches within the conversation
  - Closes #32

## Test Plan
- [ ] Click a link in chat history and verify it opens in the default browser
- [ ] Rename a tab and verify spaces can be typed
- [ ] Use `/cd <path>` and verify the directory changes while preserving conversation context
- [ ] Use `/search <query>` and verify matches are highlighted in yellow
- [ ] Use `/search` with no args to clear the search highlighting

✨ This PR was created with help from Hikari~ 🌸

Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Reviewed-on: #56
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src-tauri/src/wsl_bridge.rs

@@ -195,6 +195,13 @@ impl WslBridge {
                 cmd.args(["--mcp-config", mcp_path]);
             }
 
+            // Add resume flag if session ID provided
+            if let Some(ref session_id) = options.resume_session_id {
+                if !session_id.is_empty() {
+                    cmd.args(["--resume", session_id]);
+                }
+            }
+
             cmd.current_dir(working_dir);
 
             // Set API key as environment variable if specified
@@ -251,6 +258,13 @@ impl WslBridge {
                 claude_cmd.push_str(&format!(" --mcp-config '{}'", mcp_path));
             }
 
+            // Add resume flag if session ID provided
+            if let Some(ref session_id) = options.resume_session_id {
+                if !session_id.is_empty() {
+                    claude_cmd.push_str(&format!(" --resume '{}'", session_id));
+                }
+            }
+
             // Use bash -lc to load login profile (ensures PATH includes claude)
             cmd.args(["-e", "bash", "-lc", &claude_cmd]);