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/stores/config.ts

@@ -1,5 +1,6 @@
 import { writable, derived } from "svelte/store";
 import { invoke } from "@tauri-apps/api/core";
+import { readFile } from "@tauri-apps/plugin-fs";
 
 export type Theme = "dark" | "light" | "high-contrast" | "custom";
 export type BudgetAction = "warn" | "block";
@@ -51,11 +52,19 @@ export interface HikariConfig {
   use_worktree: boolean;
   // Disable 1M context window
   disable_1m_context: boolean;
+  // Max output tokens for Claude Code responses
+  max_output_tokens: number | null;
   // Workspaces the user has explicitly trusted
   trusted_workspaces: string[];
   // Background image settings
   background_image_path: string | null;
   background_image_opacity: number;
+  // Custom terminal font settings
+  custom_font_path: string | null;
+  custom_font_family: string | null;
+  // Custom UI font settings
+  custom_ui_font_path: string | null;
+  custom_ui_font_family: string | null;
 }
 
 const defaultConfig: HikariConfig = {
@@ -98,9 +107,14 @@ const defaultConfig: HikariConfig = {
   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,
 };
 
 function createConfigStore() {
@@ -237,6 +251,16 @@ function createConfigStore() {
     setCompactMode: async (enabled: boolean) => {
       await updateConfig({ compact_mode: enabled });
     },
+
+    setCustomFont: async (path: string | null, family: string | null) => {
+      await updateConfig({ custom_font_path: path, custom_font_family: family });
+      await applyCustomFont(path, family);
+    },
+
+    setCustomUiFont: async (path: string | null, family: string | null) => {
+      await updateConfig({ custom_ui_font_path: path, custom_ui_font_family: family });
+      await applyCustomUiFont(path, family);
+    },
   };
 }
 
@@ -302,6 +326,99 @@ export function clampFontSize(size: number): number {
   return Math.max(MIN_FONT_SIZE, Math.min(MAX_FONT_SIZE, size));
 }
 
+const DIRECT_FONT_EXTENSIONS = new Set(["woff", "woff2", "ttf", "otf", "eot"]);
+
+const FONT_MIME_MAP: Record<string, string> = {
+  woff: "font/woff",
+  woff2: "font/woff2",
+  ttf: "font/ttf",
+  otf: "font/otf",
+  eot: "application/vnd.ms-fontobject",
+};
+
+async function applyFontFromSource(path: string, family: string, styleId: string): Promise<void> {
+  const style = document.createElement("style");
+  style.id = styleId;
+
+  if (path.startsWith("http://") || path.startsWith("https://")) {
+    const ext = path.split(".").pop()?.toLowerCase() ?? "";
+
+    if (DIRECT_FONT_EXTENSIONS.has(ext)) {
+      style.textContent = `@font-face { font-family: '${family}'; src: url('${path}'); }`;
+    } else {
+      style.textContent = `@import url('${path}');`;
+    }
+  } else {
+    const data = await readFile(path);
+    const chunks: string[] = [];
+    const chunkSize = 8192;
+    for (let i = 0; i < data.length; i += chunkSize) {
+      chunks.push(String.fromCharCode(...data.slice(i, i + chunkSize)));
+    }
+    const ext = path.split(".").pop()?.toLowerCase() ?? "ttf";
+    const mime = FONT_MIME_MAP[ext] ?? "font/ttf";
+    const dataUrl = `data:${mime};base64,${btoa(chunks.join(""))}`;
+    style.textContent = `@font-face { font-family: '${family}'; src: url('${dataUrl}'); }`;
+  }
+
+  document.head.appendChild(style);
+}
+
+export async function applyCustomFont(path: string | null, family: string | null): Promise<void> {
+  if (typeof document === "undefined") return;
+
+  const styleId = "hikari-custom-font";
+  const cssVar = "--terminal-font-family";
+  const fallbackFamily = "HikariCustomFont";
+
+  document.getElementById(styleId)?.remove();
+
+  const trimmedPath = path?.trim() ?? "";
+  const trimmedFamily = family?.trim() ?? "";
+
+  if (!trimmedPath && !trimmedFamily) {
+    document.documentElement.style.removeProperty(cssVar);
+    return;
+  }
+
+  if (trimmedPath) {
+    await applyFontFromSource(trimmedPath, trimmedFamily || fallbackFamily, styleId);
+  }
+
+  if (trimmedFamily) {
+    document.documentElement.style.setProperty(cssVar, `'${trimmedFamily}', monospace`);
+  }
+}
+
+export async function applyCustomUiFont(path: string | null, family: string | null): Promise<void> {
+  if (typeof document === "undefined") return;
+
+  const styleId = "hikari-custom-ui-font";
+  const cssVar = "--ui-font-family";
+  const fallbackFamily = "HikariCustomUiFont";
+
+  document.getElementById(styleId)?.remove();
+
+  const trimmedPath = path?.trim() ?? "";
+  const trimmedFamily = family?.trim() ?? "";
+
+  if (!trimmedPath && !trimmedFamily) {
+    document.documentElement.style.removeProperty(cssVar);
+    document.body?.style.removeProperty("font-family");
+    return;
+  }
+
+  const effectiveFamily = trimmedFamily || fallbackFamily;
+
+  if (trimmedPath) {
+    await applyFontFromSource(trimmedPath, effectiveFamily, styleId);
+  }
+
+  const fontValue = `'${effectiveFamily}', sans-serif`;
+  document.documentElement.style.setProperty(cssVar, fontValue);
+  document.body?.style.setProperty("font-family", fontValue);
+}
+
 export { MIN_FONT_SIZE, MAX_FONT_SIZE, DEFAULT_FONT_SIZE };
 
 export const configStore = createConfigStore();