test(e2e): add TC-E2E-003/004/005/007/008/009/010 — delete, pagination, errors, profile, theme

- test_post_deletion.py: user delete own, admin delete any, 403 for other's
- test_pagination.py: navigation across pages, boundary on last page
- test_errors.py: 404 nonexistent post, 404 for other user's draft
- test_post_lifecycle.py: draft-to-publish via edit flow
- test_post_ownership.py: user can edit own post
- test_profile_and_theme.py: profile page rendering, theme toggle with localStorage
- fix(web): remove infinite pagination for USER role (routes.py)
- fix(e2e): stabilize all publish() calls with expect_navigation
- fix(e2e): add _unique_title() to avoid slug collisions at scale
- docs: update FEATURE_POST_LIFECYCLE.md and TEST_MODEL.md coverage

tests/e2e/pages/__init__.py

@@ -81,6 +81,53 @@ class HomePage(BasePage):
         """
         return self._empty_state.is_visible(self.page)
 
+    def count_posts(self) -> int:
+        """Count the number of post cards on the page.
+
+        Returns:
+            Number of visible post cards.
+        """
+        return self.page.locator('article[data-testid^="post-card-"]').count()
+
+    def get_current_page(self) -> int:
+        """Get the current pagination page number.
+
+        Returns:
+            Current page number as integer.
+        """
+        text = self.page.locator('[data-testid="pagination-current"]').text_content()
+        return int(text) if text else 1
+
+    def can_go_next(self) -> bool:
+        """Check if the next page link is enabled.
+
+        Returns:
+            True if the next pagination control is a clickable link.
+        """
+        tag = self.page.locator('[data-testid="pagination-next"]').evaluate(
+            "el => el.tagName.toLowerCase()"
+        )
+        return tag == "a"
+
+    def can_go_prev(self) -> bool:
+        """Check if the previous page link is enabled.
+
+        Returns:
+            True if the previous pagination control is a clickable link.
+        """
+        tag = self.page.locator('[data-testid="pagination-prev"]').evaluate(
+            "el => el.tagName.toLowerCase()"
+        )
+        return tag == "a"
+
+    def go_to_next_page(self) -> None:
+        """Click the next page pagination link."""
+        self.page.locator('[data-testid="pagination-next"]').click()
+
+    def go_to_prev_page(self) -> None:
+        """Click the previous page pagination link."""
+        self.page.locator('[data-testid="pagination-prev"]').click()
+
 
 class PostFormPage(BasePage):
     """Page object for the new post / edit post form.
@@ -223,3 +270,8 @@ class PostDetailPage(BasePage):
             True if delete button is present.
         """
         return self._delete_btn.is_visible(self.page)
+
+    def delete(self) -> None:
+        """Click the delete button and accept the confirmation dialog."""
+        self.page.on("dialog", lambda dialog: dialog.accept())
+        self._delete_btn.click(self.page)