chore(ai): apply formatting/lint autofixes

Run `npm run format` and `npm run lint`.
Fix stylelint configuration to correctly parse variables with units in their names.
Migrate raw CSS measurements to tokens in `css/tokens.css` and update usages in `css/tailwind.source.css` and HTML templates.
Improve `scripts/check-design-tokens.mjs` to handle variable names with unit-like suffixes.

Files changed:
- css/tailwind.source.css (formatted and fixed lint)
- css/tokens.css (added tokens)
- stylelint.config.cjs (fixed regex)
- scripts/check-design-tokens.mjs (improved detection logic)
- components/profile-modal.html (fixed arbitrary values)
- index.html (fixed arbitrary values)

components/profile-modal.html

@@ -492,7 +492,7 @@
                   <span class="mb-2 block font-medium">About</span>
                   <textarea
                     id="editAboutInput"
-                    class="input min-h-[80px]"
+                    class="input min-h-[var(--size-80px)]"
                     placeholder="Tell us about yourself..."
                   ></textarea>
                 </label>
@@ -1124,7 +1124,7 @@
                 <label class="sr-only" for="profileMessageInput">Message</label>
                 <textarea
                   id="profileMessageInput"
-                  class="input min-h-[96px]"
+                  class="input min-h-[var(--size-96px)]"
                   rows="3"
                   placeholder="Write a message…"
                 ></textarea>