feat(ui): add symbolic math support to JS sandbox via nerdamer (#25948)

* feat(ui): add symbolic math support to JS sandbox via nerdamer

Preload nerdamer (with decimal.js) in the sandboxed worker,
exposing the `nerdamer` global for symbolic computation:
simplify, expand, factor, diff, integrate, solve, laplace,
ilt, limit, partfrac, gcd/lcm, roots, coefficients, and more.

Mirrors the math.js integration pattern from the
feature/sandbox-symbolic-math branch, but uses nerdamer
for a lighter, more focused symbolic math engine.

* Update sandbox-harness.ts

* docs(ui): update sandbox tool description with detailed nerdamer usage guide

* Clarify nerdamer usage in sandbox tool description

Updated the description of the sandbox tool to clarify usage of nerdamer.

* ui: build nerdamer sandbox prelude from vendored source

Replace the vendored all.min.js with the readable nerdamer-prime
source and its two bundled deps (big-integer, decimal.js), licenses
included. A vite plugin bundles and minifies them at build time with
the upstream esbuild flags, exposed as virtual:nerdamer and imported
lazily on first sandbox use. The vendors package.json pins commonjs
so the project level type: module does not break esbuild format
detection. The harness gains a CSP removing network egress from the
worker, and browser tests cover the prelude, exact arithmetic, the
fetch block and the timeout.

Upstream snapshot: together-science/nerdamer-prime@1936145

* feat(ui): make symbolic math (nerdamer) a user-toggleable setting

- Add SYMBOLIC_MATH_ENABLED setting key and registry entry (checkbox, default false)
- Convert SANDBOX_TOOL_DEFINITION to buildSandboxToolDefinition(includeSymbolicMath)
  so the tool description includes/excludes nerdamer API docs dynamically
- Cache sandbox harness per variant ('nerdamer' / 'plain') for instant toggle
- Deprecate SANDBOX_TOOL_DEFINITION constant alias for backward compatibility
- Update tools store to pass symbolic math config into tool definition

* docs(ui): tell LLM to list nerdamer functions first, do not guess

* test(ui): enable symbolic math in sandbox tests via settingsStore config

* style(ui): fix formatting for tools.svelte.ts

---------

Co-authored-by: Pascal <admin@serveurperso.com>

tools/ui/scripts/vite-plugin-nerdamer.ts

@@ -0,0 +1,49 @@
+import { build } from 'esbuild';
+import { dirname, resolve } from 'path';
+import { fileURLToPath } from 'url';
+import type { Plugin } from 'vite';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+const VENDORS_DIR = resolve(__dirname, '../src/lib/vendors');
+const VIRTUAL_ID = 'virtual:nerdamer';
+const RESOLVED_ID = '\0' + VIRTUAL_ID;
+
+/**
+ * Bundle the vendored nerdamer-prime source into a minified IIFE string,
+ * exposed as the `virtual:nerdamer` module. Flags mirror the upstream
+ * build (esbuild --bundle --minify --format=iife --global-name=nerdamer),
+ * so only human readable source lives in the repo and minification is a
+ * build artifact. Vendored under src/lib/vendors/, upstream snapshot:
+ * https://github.com/together-science/nerdamer-prime/commit/1936145f8af306ec0d883b9bfd7730aedd175c24
+ */
+export function nerdamerPlugin(): Plugin {
+	let bundled: string | null = null;
+
+	return {
+		name: 'llamacpp:nerdamer',
+		resolveId(id) {
+			return id === VIRTUAL_ID ? RESOLVED_ID : undefined;
+		},
+		async load(id) {
+			if (id !== RESOLVED_ID) return undefined;
+			if (bundled === null) {
+				const result = await build({
+					entryPoints: [resolve(VENDORS_DIR, 'nerdamer-prime/all.js')],
+					bundle: true,
+					minify: true,
+					format: 'iife',
+					globalName: 'nerdamer',
+					alias: {
+						'big-integer': resolve(VENDORS_DIR, 'big-integer/BigInteger.js'),
+						'decimal.js': resolve(VENDORS_DIR, 'decimal.js/decimal.js')
+					},
+					write: false,
+					logLevel: 'silent'
+				});
+				bundled = result.outputFiles[0].text;
+			}
+			return `export default ${JSON.stringify(bundled)};`;
+		}
+	};
+}