Use the card view's inline back arrow on every other heading

Generalized .card-view__back into .title-back and applied it to:

- ProjectView: arrow back to the dashboard, inline before the title
  (previously no back link at all here -- the app bar's brand already
  covers it, but this is more discoverable and matches the others).
- ProjectConfigureView: arrow back to the project, replacing the
  separate "Back to project" button that used to sit in the actions
  corner next to Manage.
- ProfileView: arrow back to the dashboard, replacing the plain-text
  link removed in an earlier commit.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/style.css

@@ -647,22 +647,18 @@ h1 {
   }
 }
 
-.project-head__back {
-  display: inline-flex;
-  align-items: center;
-  text-decoration: none;
-}
-
-/* The card view's back link sits inside its title, right before the card's
-   text, rather than up in .project-head__actions like the other views. */
-.card-view__back {
+/* An arrow inline in a heading, right before the title text -- back to
+   wherever this page is "inside" of (dashboard, a project, ...). Used by
+   every heading that has one instead of a separate button, so they all
+   look and behave the same. */
+.title-back {
   display: inline-flex;
   margin-right: 0.4rem;
   color: var(--muted);
   text-decoration: none;
 }
 
-.card-view__back:hover {
+.title-back:hover {
   color: var(--accent);
 }