ci: add GitHub Actions workflows with semantic-release auto-versioning

chore: fix all 702 clippy warnings across codebase
- auto-fix 475 via cargo clippy --fix
- fix remaining 227 manually: uninlined_format_args, redundant_closure, match_same_arms,
  underscore_binding, format_push_string, items_after_statements, needless_pass_by_value,
  clone_on_copy, case_sensitive_extension, single_match/let-else, write_with_newline,
  and other clippy lints

src/model/msglog/blobs.rs

@@ -1,4 +1,4 @@
-//! Binary blob storage in the message-log SQLite database (e.g. images,
+//! Binary blob storage in the message-log `SQLite` database (e.g. images,
 //! attachments), keyed by session id and an arbitrary blob key.
 
 use rusqlite::{Connection, params};
@@ -9,7 +9,7 @@ use anyhow::Result;
 /// Flow: compute current timestamp → `INSERT OR REPLACE` into `blobs`
 /// keyed on `(session_id, blob_key)`.
 ///
-/// Return: `Ok(())` on success, or the underlying SQLite error.
+/// Return: `Ok(())` on success, or the underlying `SQLite` error.
 pub fn store_blob(conn: &Connection, session_id: &str, blob_key: &str, data: &[u8], mime_type: Option<&str>) -> Result<()> {
     let created_at = chrono::Utc::now().timestamp_millis();
     conn.execute(
@@ -22,7 +22,7 @@ pub fn store_blob(conn: &Connection, session_id: &str, blob_key: &str, data: &[u
 /// Fetch a blob's bytes for a session by key.
 ///
 /// Return: `Ok(Some(data))` if found, `Ok(None)` if no matching row
-/// exists, `Err` for any other SQLite failure.
+/// exists, `Err` for any other `SQLite` failure.
 pub fn retrieve_blob(conn: &Connection, session_id: &str, blob_key: &str) -> Result<Option<Vec<u8>>> {
     let result = conn.query_row(
         "SELECT data FROM blobs WHERE session_id = ?1 AND blob_key = ?2",
@@ -52,7 +52,7 @@ pub fn delete_blob(conn: &Connection, session_id: &str, blob_key: &str) -> Resul
 /// List all blob keys stored for a session, oldest first.
 ///
 /// Return: `Ok(Vec<String>)` of keys ordered by `created_at`, or the
-/// underlying SQLite error.
+/// underlying `SQLite` error.
 pub fn list_blob_keys(conn: &Connection, session_id: &str) -> Result<Vec<String>> {
     let mut stmt = conn.prepare(
         "SELECT blob_key FROM blobs WHERE session_id = ?1 ORDER BY created_at ASC"

src/model/msglog/mod.rs

@@ -12,7 +12,7 @@ pub use query::insert_message;
 /// schema is initialized.
 ///
 /// Flow: resolve `<session_dir>/messages.sqlite` → create parent dirs →
-/// open a SQLite connection → run `schema::init_schema`.
+/// open a `SQLite` connection → run `schema::init_schema`.
 ///
 /// Return: an open, schema-ready `Connection`, or an error if any step
 /// fails.

src/model/msglog/query.rs

@@ -6,7 +6,7 @@ use crate::dto::chat::message::{ChatMessage, Role};
 
 /// Insert a chat message into the session's message log.
 ///
-/// Flow: extract optional content/tool_call_id/tool_name → serialize
+/// Flow: extract optional `content/tool_call_id/tool_name` → serialize
 /// `tool_calls` to a JSON string if present → map `Role` to its string
 /// column value → `INSERT` the row with the current timestamp.
 ///

src/model/msglog/schema.rs

@@ -1,4 +1,4 @@
-//! SQLite schema definition for the message log database.
+//! `SQLite` schema definition for the message log database.
 
 use rusqlite::Connection;
 use anyhow::Result;
@@ -9,7 +9,7 @@ use anyhow::Result;
 /// Why: idempotent via `CREATE TABLE/INDEX IF NOT EXISTS`, so it's safe
 /// to call on every `open_or_create`.
 ///
-/// Return: `Ok(())` on success, or the underlying SQLite error.
+/// Return: `Ok(())` on success, or the underlying `SQLite` error.
 pub fn init_schema(conn: &Connection) -> Result<()> {
     conn.execute_batch("PRAGMA foreign_keys = ON;")?;
     conn.execute_batch(