Feat/rerank model (#2137)

* feat(provider): add rerank model management as a core model type

* feat(provider): add rerank support to existing requesters and new rerank providers

* feat(web): add rerank model management UI and pipeline config

* fix(provider): correct rerank support_type after verification

- Add rerank to OpenRouter (confirmed /api/v1/rerank endpoint)
- Remove rerank from Ollama (no native support, PR #7219 unmerged)
- Remove rerank from JiekouAI (no rerank docs found, URL path mismatch)

* fix(provider): remove alru_cache from model getters and add rerank param hints

* fix: resolve lint errors

- Remove unused alru_cache import from modelmgr.py
- Remove unused error_message variable in invoke_rerank
- Fix prettier formatting in frontend files

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: remove unused exception variable

- Change `except Exception as e:` to `except Exception:` since e is not used
- Fix prettier formatting in ProviderCard.tsx

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: apply ruff format

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* feat(template): add rerank config fields to default pipeline config

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* chore: remove PR.md

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix(ui): remove duplicate rerank model form in AddModelPopover

The form was being rendered twice: once in TabsContent manual mode
and again in a separate conditional block for rerank tab.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

src/langbot/templates/default-pipeline-config.json

@@ -52,7 +52,9 @@
                     "content": "You are a helpful assistant."
                 }
             ],
-            "knowledge-bases": []
+            "knowledge-bases": [],
+            "rerank-model": "",
+            "rerank-top-k": 5
         },
         "dify-service-api": {
             "base-url": "https://api.dify.ai/v1",