feat: multiple UI improvements, font settings, and memory file display names (#175)

## Summary

- **fix**: `show_thinking_blocks` setting now persists across sessions — it was defined on the TypeScript side but missing from the Rust `HikariConfig` struct, so serde silently dropped it on every save/load
- **feat**: Tool calls are now rendered as collapsible blocks matching the Extended Thinking block aesthetic, replacing the old inline dropdown approach
- **feat**: Add configurable max output tokens setting
- **feat**: Use random creative names for conversation tabs
- **test**: Significantly expanded frontend unit test coverage
- **docs**: Require tests for all changes in CLAUDE.md
- **feat**: Allow users to specify a custom terminal font (Closes #176)
- **feat**: Display friendly names for memory files derived from the first heading (Closes #177)
- **feat**: Add custom UI font support for the app chrome (buttons, labels, tabs)
- **fix**: Apply custom UI font to the full app interface — `.app-container` was hardcoded, blocking inheritance from `body`; also renamed "Custom Font" to "Custom Terminal Font" for clarity

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #175
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/lib/components/StatusBar.svelte

@@ -107,9 +107,14 @@
     show_thinking_blocks: true,
     use_worktree: false,
     disable_1m_context: false,
+    max_output_tokens: null,
     trusted_workspaces: [],
     background_image_path: null,
     background_image_opacity: 0.3,
+    custom_font_path: null,
+    custom_font_family: null,
+    custom_ui_font_path: null,
+    custom_ui_font_family: null,
   });
 
   let streamerModeActive = $state(false);
@@ -185,6 +190,7 @@
           allowed_tools: allAllowedTools,
           use_worktree: currentConfig.use_worktree ?? false,
           disable_1m_context: currentConfig.disable_1m_context ?? false,
+          max_output_tokens: currentConfig.max_output_tokens ?? null,
         },
       });
 
@@ -344,6 +350,7 @@
           allowed_tools: allAllowedTools,
           use_worktree: currentConfig.use_worktree ?? false,
           disable_1m_context: currentConfig.disable_1m_context ?? false,
+          max_output_tokens: currentConfig.max_output_tokens ?? null,
         },
       });