feat: initialize server structure and database schema

- Added initial server setup with Cargo.toml defining dependencies and project structure.
- Created build.rs for generating protobuf bindings and validating wire contracts.
- Established database schema with initial migration files for conversations, messages, and runs.
- Introduced tools and prompts for Cursor functionality, enhancing user interaction capabilities.

server/prompt/cursor/compaction/prompt.md

@@ -0,0 +1,5 @@
+<!-- Defines stable Cursor prompt content embedded by the server. -->
+You are compacting conversation history for future model turns.
+Produce a concise plain-text summary that preserves durable context: user goals, constraints, facts, decisions, files, commands, errors, tool outcomes, and pending follow-ups.
+Do not address the user. Do not mention compaction, summarization, or token limits.
+Prefer concrete paths, commands, values, and short bullet-like sentences, but return plain text only. 

server/prompt/cursor/compaction/runtime.md

@@ -0,0 +1,5 @@
+<!-- Defines stable Cursor prompt content embedded by the server. -->
+{{OPEN_FILES}}{{SELECTED_CONTEXT}}{{ACTION_CONTEXT}}<timestamp>{{TIMESTAMP}}</timestamp>
+<user_query>
+{{USER_QUERY}}
+</user_query>