v0.8.0-rc4

## What's Changed

### ✨ Features

* 🌐 Add support to SubDirectory hosting by @jpsfs in https://github.com/danny-avila/LibreChat/pull/9155
* 📎 Upload as Text Support for Plaintext, Audio, RAG, and Token Limits by @danny-avila in https://github.com/danny-avila/LibreChat/pull/8868, https://github.com/danny-avila/LibreChat/pull/9356
* 🔧 Alternative DNS Lookup for AWS ElastiCache TLS Connections by @MarcAmick in https://github.com/danny-avila/LibreChat/pull/9264
* 🎨 MCP UI integration by @samuelpath in https://github.com/danny-avila/LibreChat/pull/9299, https://github.com/danny-avila/LibreChat/pull/9418, https://github.com/danny-avila/LibreChat/pull/9581
* 🔐 Add Configurable Min. Password Length by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9315
* 🎤 Cumulative Transcription Support for `AudioRecorder` & External STT by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9316, https://github.com/danny-avila/LibreChat/pull/9318
* 🔢 Add Support for Integer and Float JSON Schema Types by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9469
* 🗄️ Allow Skipping Transactions When Balance is Disabled by @sbruel in https://github.com/danny-avila/LibreChat/pull/9419
* 🗣️ Language Support for OpenAI Speech-to-Text by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9470
* 📋 Support Custom Content-Types in Action Descriptors by @sbruel in https://github.com/danny-avila/LibreChat/pull/9364
* 🔗 Custom Jina API URL for Web Search Reranking by @dan-and in https://github.com/danny-avila/LibreChat/pull/9236
* 🎚️ Anthropic Parameter Set Support via Custom Endpoints by @dustinhealy in https://github.com/danny-avila/LibreChat/pull/9415
* 😶‍🌫️ Conditionally Hide Tools Dropdown  by @dustinhealy in https://github.com/danny-avila/LibreChat/pull/9530
* 🔌 Revoke MCP OAuth Credentials by @ruggishop in https://github.com/danny-avila/LibreChat/pull/9464
* ⛑️ add Helm `serviceAccount` Configuration by @jessebye in https://github.com/danny-avila/LibreChat/pull/9606

### 🔧 Refactoring

* 🛜 Streamline App Config Usage by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9234, https://github.com/danny-avila/LibreChat/pull/9366, https://github.com/danny-avila/LibreChat/pull/9367, https://github.com/danny-avila/LibreChat/pull/9438, https://github.com/danny-avila/LibreChat/pull/9558
* 🎯 Custom Endpoint Request-based Header Resolution by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9344
* 🗃️ File Access via Agent; Deny Deletion if not Editor, Allow Viewer by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9357
* 📇 Improve State mgmt. for File uploads and Tool Auth by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9359
* ✂️ MCP UI Separation for Agents by @dustinhealy and @danny-avila in https://github.com/danny-avila/LibreChat/pull/9237, https://github.com/danny-avila/LibreChat/pull/9471
* ⬆️ Enable File Search from Upload Option by @usnavy13 in https://github.com/danny-avila/LibreChat/pull/9425
* 🌒 Theme Handling to use `isDark` Utility by @Educg550 in https://github.com/danny-avila/LibreChat/pull/9405
* 🦾 Filter Model Specs Based on User Access to Agents by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9433
* 🛂 Centralize `fileStrategy` Resolution for OpenID, SAML, and Social Logins by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9468
* 🚃 Normalize paths for Vite Config Chunking by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9513
* 👻 LocalStorage Cleanup and MCP State Optimization by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9528
* 📂 Show File Search and Code File Upload Options Based on Agent Tools by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9532
* 📬 Improved Rendering and Localization for Drag & Drop Files by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9547
* 🤖 Auto-validate IDs in Agent Query by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9555
* 🔧 Centralize Collection Checks for Permissions Migration by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9565
* 🔒 Optimize Email Domain Validation in OpenID, SAML, and Social Logins by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9567, https://github.com/danny-avila/LibreChat/pull/9566
* 🔐 Improve MCP OAuth Event Handler Cleanup by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9584, https://github.com/danny-avila/LibreChat/pull/9589
* 🔍 Preserve Category in Agent Marketplace Search by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9598
* ⌛ Add Effective Timeout for MCP Fetch by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9585

### ⚙️ Other Changes

* 🐋 switch from `ankane/pgvector` to `pgvector/pgvector` by @ethanlaj in https://github.com/danny-avila/LibreChat/pull/9245
* 🧹 Remove `dangerouslySetHtml` by @colinlin-stripe in https://github.com/danny-avila/LibreChat/pull/9288
* 🧪 Tests for Anthropic and OpenAI LLM Configuration by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9484
* 🧹 Remove Unused Cache Configuration Keys by @nhtruong in https://github.com/danny-avila/LibreChat/pull/9551
* ⚙️ Update Build Config due to Windows Tests by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9511
* 📦 Update `caniuse-lite` to v1.0.30001741, `vite` to v6.3.6, `axios` to v1.12.1 by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9523, https://github.com/danny-avila/LibreChat/pull/9553, https://github.com/danny-avila/LibreChat/pull/9600

### 🐛 Fixes

* 💲 Prevent Single-dollar LaTeX for abbrev. Currency (K, M, B) by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9293
* 📧 Missing Email fallback in `openIdJwtLogin` by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9311
* 🐛 String Interpolation in Messages Endpoint from #9155 by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9312
* 🔧 MCP Selection Persist and UI Flicker Issues by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9324
* 🛠️ resolve broken file downloads from assistants API (Web ReadableStream support) by @arthurian in https://github.com/danny-avila/LibreChat/pull/9200
* 🗺️ Embedded file handling to use Proper Filename by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9372
* 🗨️ Prompts Pagination by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9385
* 🌟 Add Composite Indexes to Agent Categories for CosmosDB Compatibility by @mforman in https://github.com/danny-avila/LibreChat/pull/9430
* 🔐 Image Validation when Reusing OpenID Token  by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9458
* 🔍 Display File Search Citations Based on Permissions by @benverhees in https://github.com/danny-avila/LibreChat/pull/9454
* ⚙️ Dynamic HPA API Version Selection for K8s Compatibility by @pranshu-m in https://github.com/danny-avila/LibreChat/pull/9320
* 🌐 Prevent MCP Body/Header Timeouts at 5-Minute mark by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9476
* 🔒 Update Token Deletion To Prevent Undefined Field Queries by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9477
* 🔐 Resolve Env. Variables for MCP OAuth Manual Config by @devilb2103 in https://github.com/danny-avila/LibreChat/pull/9501
* 🔒 Memory Disabled Config UI Permissions by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9522
* 🔻 Role and System Message Handling for ChatGPT Imports by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9524
* 🏪 Show Agent Builder in Marketplace by @ruggishop in https://github.com/danny-avila/LibreChat/pull/9537
* 🔖 Agent Marketplace Bookmark and New Chat buttons by @ruggishop in https://github.com/danny-avila/LibreChat/pull/9549
* 🪄 MCP UI Renders for OAuth and Custom User Vars Servers by @dustinhealy in https://github.com/danny-avila/LibreChat/pull/9559
* 🔃 Token Refresh in Browser Only, Redirect on Refresh Failure by @danny-avila in https://github.com/danny-avila/LibreChat/pull/9583
* 🐳 Add missing `uploads` directory to Dockerfile by @sichgeis in https://github.com/danny-avila/LibreChat/pull/9590
* 🪟 Auto-fetch agents to fill Viewport in Marketplace Scroll by @sbruel in https://github.com/danny-avila/LibreChat/pull/9591
* ⛑️ follow postgres bitnami values schema in rag-api helm chart by @mmdaz in https://github.com/danny-avila/LibreChat/pull/7782

### 🌍 Internationalization

🌍 Add Slovenian Language by @dustinhealy in https://github.com/danny-avila/LibreChat/pull/9313
🌍 Update translation.json with latest translations in https://github.com/danny-avila/LibreChat/pull/9321, https://github.com/danny-avila/LibreChat/pull/9361, https://github.com/danny-avila/LibreChat/pull/9381, https://github.com/danny-avila/LibreChat/pull/9434, https://github.com/danny-avila/LibreChat/pull/9439, https://github.com/danny-avila/LibreChat/pull/9473, https://github.com/danny-avila/LibreChat/pull/9515, https://github.com/danny-avila/LibreChat/pull/9533, https://github.com/danny-avila/LibreChat/pull/9570, https://github.com/danny-avila/LibreChat/pull/9586, https://github.com/danny-avila/LibreChat/pull/9599

## New Contributors
* @jpsfs made their first contribution in https://github.com/danny-avila/LibreChat/pull/9155
* @ethanlaj made their first contribution in https://github.com/danny-avila/LibreChat/pull/9245
* @colinlin-stripe made their first contribution in https://github.com/danny-avila/LibreChat/pull/9288
* @MarcAmick made their first contribution in https://github.com/danny-avila/LibreChat/pull/9264
* @mforman made their first contribution in https://github.com/danny-avila/LibreChat/pull/9430
* @Educg550 made their first contribution in https://github.com/danny-avila/LibreChat/pull/9405
* @dan-and made their first contribution in https://github.com/danny-avila/LibreChat/pull/9236
* @devilb2103 made their first contribution in https://github.com/danny-avila/LibreChat/pull/9501
* @sichgeis made their first contribution in https://github.com/danny-avila/LibreChat/pull/9590
* @mmdaz made their first contribution in https://github.com/danny-avila/LibreChat/pull/7782
* @jessebye made their first contribution in https://github.com/danny-avila/LibreChat/pull/9606

**Full Changelog**: https://github.com/danny-avila/LibreChat/compare/v0.8.0-rc3...v0.8.0-rc4