Add safe URL construction rules to agent guides

Add a URL and query parameter construction section to
contrib/claude/go-style.md requiring net/url (url.JoinPath,
url.Values, url.Parse) instead of fmt.Sprintf or string
concatenation.

Create contrib/claude/ts-style.md with matching TypeScript
rules requiring URL and URLSearchParams instead of template
literals or string concatenation.

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

contrib/claude/ts-style.md

@@ -0,0 +1,32 @@
+# TypeScript Style
+
+## URL and query parameter construction
+
+**Never** build URLs with template literals, string concatenation, or string formatting. Always use the `URL` and `URLSearchParams` APIs.
+
+- Use `new URL()` to construct or parse full URLs.
+- Use `URLSearchParams` to build query strings.
+- Use `.pathname`, `.searchParams`, and other `URL` properties to modify parts of a URL safely.
+- Use `encodeURIComponent` for dynamic path segments.
+
+```typescript
+// Bad — template literal
+const endpoint = `https://api.example.com/users/${userId}?active=${active}`;
+
+// Bad — string concatenation
+const endpoint = "https://api.example.com/orgs/" + orgId + "/members";
+
+// Bad — query params via string concat
+const qs = "?domain=" + domain + "&limit=100";
+
+// Good — URL object
+const url = new URL("https://api.example.com");
+url.pathname = `/users/${encodeURIComponent(userId)}`;
+url.searchParams.set("active", String(active));
+
+// Good — URLSearchParams for query strings
+const params = new URLSearchParams();
+params.set("domain", domain);
+params.set("limit", "100");
+const qs = params.toString();
+```