Add redirect support, live candidate list, per-article save count, and error pages

- Detect redirect targets (e.g. "handling stolen goods" → "Possession of
  stolen goods") and use piped links [[target|title]] in edits; exclude
  articles already linking to the redirect target from candidates
- Remove candidates from the list in real time as they are checked and
  found invalid, with live count update in the summary
- Track and display per-article save count in the stats line
- Rename "Find Link" to "Missing Link" throughout
- Show redirect target in the article heading
- Report save errors to the user via error page instead of crashing
- Filter self-links using case-insensitive first-letter comparison

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web_view.py

@@ -96,14 +96,20 @@ def search_count(q: str) -> int:
     return get_hit_count(article_title_to_search_query(q)) - 1
 
 
-def search_count_with_link(q: str) -> int:
+def search_count_with_link(q: str, redirect_to: str | None = None) -> int:
     """Articles in Wikipedia that include this search term and a link."""
-    return get_hit_count(article_title_to_search_query(q) + f' linksto:"{q}"')
+    count = get_hit_count(article_title_to_search_query(q) + f' linksto:"{q}"')
+    if redirect_to:
+        count += get_hit_count(article_title_to_search_query(q) + f' linksto:"{redirect_to}"')
+    return count
 
 
-def search_no_link(q: str) -> tuple[int, list[Hit]]:
+def search_no_link(q: str, redirect_to: str | None = None) -> tuple[int, list[Hit]]:
     """Search for mentions of article title with no link included."""
-    query = run_search(article_title_to_search_query(q) + f' -linksto:"{q}"', "max")
+    exclude = f' -linksto:"{q}"'
+    if redirect_to:
+        exclude += f' -linksto:"{redirect_to}"'
+    query = run_search(article_title_to_search_query(q) + exclude, "max")
     return (query["searchinfo"]["totalhits"], query["search"])
 
 
@@ -313,9 +319,15 @@ def handle_post(url_title: str) -> Response:
         do_save(from_title, hit_title)
     except mediawiki_oauth.LoginNeeded:
         return flask.redirect(flask.url_for("start_oauth"))
-    except mediawiki_api.APIError as e:
-        return flask.make_response(f"Save failed: {e}", 502)
+    except (mediawiki_api.APIError, api.MediawikiError) as e:
+        return flask.make_response(
+            flask.render_template("error.html", message=f"Save failed: {e}"), 502
+        )
     flask.session["saves"] = flask.session.get("saves", 0) + 1
+    saves_by_title: dict[str, int] = flask.session.get("saves_by_title", {})
+    saves_by_title[from_title] = saves_by_title.get(from_title, 0) + 1
+    flask.session["saves_by_title"] = saves_by_title
+    flask.session.modified = True
     _record_skip(from_title, hit_title)
     return flask.redirect(
         flask.url_for("article_page", url_title=url_title, after=hit_title)
@@ -330,10 +342,15 @@ def article_page(url_title: str) -> str | Response:
 
     from_title = url_title.replace("_", " ").strip()
 
+    try:
+        redirect_to = api.get_wiki_info(from_title)
+    except (api.MissingPage, api.MultipleRedirects, api.MediawikiError):
+        redirect_to = None
+
     try:
         total = search_count(from_title)
-        with_link = search_count_with_link(from_title)
-        _no_link_count, hits = search_no_link(from_title)
+        with_link = search_count_with_link(from_title, redirect_to)
+        _no_link_count, hits = search_no_link(from_title, redirect_to)
     except api.MediawikiError as e:
         return flask.make_response(
             flask.render_template("error.html", message=str(e)), 502
@@ -362,13 +379,17 @@ def article_page(url_title: str) -> str | Response:
     if not hits:
         return flask.render_template("all_done.html")
 
+    saves_this_session = flask.session.get("saves_by_title", {}).get(from_title, 0)
+
     return flask.render_template(
         "article.html",
         title=from_title,
+        redirect_to=redirect_to,
         total=total,
         with_link=with_link,
         hits=hits,
         url_title=url_title,
+        saves_this_session=saves_this_session,
     )
 
 
@@ -376,7 +397,12 @@ def do_save(title: str, hit_title: str) -> str:
     """Update page on Wikipedia."""
     token = mediawiki_oauth.get_token()
 
-    found = get_match(title, hit_title, None)
+    try:
+        redirect_to = api.get_wiki_info(title)
+    except (api.MissingPage, api.MultipleRedirects, api.MediawikiError):
+        redirect_to = None
+
+    found = get_match(title, hit_title, redirect_to)
 
     summary = (
         f"link [[{found['replacement']}]] using [[:en:User:Edward/Find link|Find link]]"
@@ -417,9 +443,10 @@ def api_valid_hit() -> werkzeug.wrappers.response.Response:
     """Check if a candidate article has a valid unlinked mention."""
     link_to = flask.request.args["link_to"]
     link_from = flask.request.args["link_from"]
+    redirect_to = flask.request.args.get("redirect_to") or None
 
     try:
-        found = get_diff(link_to, link_from, None)
+        found = get_diff(link_to, link_from, redirect_to)
     except NoMatch:
         _record_skip(link_to, link_from)
         return flask.jsonify(valid=False)