Coder / Agent improvements

• [Theia AI] Coder ChangeSet minor issue - Delete the change set when all changes are deleted #15048
• [Theia AI] Diff editor line wrapping #15105
• [Theia AI] Add function to validate a file #14973
• Diff markers lost when diff editor hidden #15178
• [Theia AI] Allow project specific prompt additions (e.g. workspace structure) #15200
• [Theia AI] Sonnet tends to always rewrite a file if content is added #15357

Chat View improvements

• [Theia AI] Pin Agent - minor issue: need to add space after this operation #15051
• [Theia AI] Hashtags always autocomplete in the chat #15028
• Code blocks show a focus border at the bottom, we probably need a similar fix as for the Chat Input (fixed with chore(chat): minor chat style improvements #15112)
• chore(chat): minor chat style improvements #15112
• [Theia AI] Paste does not work in the right-click menu of chat input #15054
• [Theia AI] Consolidate widget labels #15303
• feat(chat): add customizable welcome message #15316
• Make it easier to find chat sessions by properly naming them #15115
• chore: improve style of code blocks in modern theme #15351
• chore: remove outline in the chat session settings editor #15356
• Enable showing custom UI while certain LLM responses are streamed #15386

General Features

• [Theia AI] Support prompt fragments #14899
• Allow to add all MCP functions to a prompt without listing them explicitly #14952
• Add MCP Server config view to AI Configuration #15280
• initial thinking support for claude #15092
• [Theia AI] Add LLMSettings to UI #15100
• [Theia AI] Support Gemini API #15247

General Improvements

• [Theia AI] Add gpt-4.5-preview as a default model #15089
• [Theia AI] Agent settings do not validate in preferences #15174
• [Theia AI] Increase Anthropics default max token #15195
• [Theia AI] Agent settings, AI settings and history view should be reachable from the chat #15190
• [Theia AI] Add reference to AI configuration view in the settings #15160
• Support AI variable dependencies explicitly #15000
• [Theia AI] Put all prompts under MIT #15158
• [Theia AI] Add shortcut for adding the current file #15251
• [Theia AI] Refine AI configuration settings descriptions #15249
• [Theia AI] Tool Calling with OpenAI API Bug/Improvement: Ensure each function has a clear schema #14663
• Support variable auto completion in AI prompt editor #15202
• getFileDiagnostics does not complete #15299
• [Theia AI] Turn automatic inline code completion off by default #15332
• feat: centralize LLM communication tracking in chat model #15146