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/view/chat.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::cast_possible_truncation, clippy::cast_sign_loss, clippy::cast_precision_loss, clippy::cast_possible_wrap)]
 //! Chat transcript panel rendering — message cards with role badges.
 //!
 //! Flow: `draw_chat` turns `state.transcript_cache.messages` into a
@@ -19,7 +20,7 @@ use ratatui::Frame;
 use super::theme::Theme;
 
 /// Break a flat run of styled spans into `Line`s at embedded `\n` boundaries.
-fn split_spans_into_lines<'a>(spans: Vec<Span<'a>>) -> Vec<Line<'a>> {
+fn split_spans_into_lines(spans: Vec<Span<'_>>) -> Vec<Line<'_>> {
     let mut lines = Vec::new();
     let mut current_spans = Vec::new();
 
@@ -76,10 +77,11 @@ fn format_timestamp(ts: i64) -> String {
     let secs = ts / 1000;
     let mins = (secs / 60) % 60;
     let hrs = (secs / 3600) % 24;
-    format!("{:02}:{:02}", hrs, mins)
+    format!("{hrs:02}:{mins:02}")
 }
 
 /// Render the scrollable chat transcript panel with message card styling.
+#[allow(clippy::too_many_lines)]
 pub fn draw_chat(frame: &mut Frame, area: Rect, state: &crate::app::state::rest::AppStateRest) {
     let messages = &state.transcript_cache.messages;
     let scroll_offset = state.scroll.offset;
@@ -95,7 +97,7 @@ pub fn draw_chat(frame: &mut Frame, area: Rect, state: &crate::app::state::rest:
     };
 
     // ── Render messages as cards ─────────────────────────────────────────
-    for (_msg_idx, msg) in messages.iter().enumerate() {
+    for msg in messages {
         let accent = role_accent_color(&msg.role);
         let badge = role_badge(&msg.role);
         let label = role_label(&msg.role);
@@ -119,12 +121,12 @@ pub fn draw_chat(frame: &mut Frame, area: Rect, state: &crate::app::state::rest:
             ),
             // Role name
             Span::styled(
-                format!(" {}", label),
+                format!(" {label}"),
                 Style::default().fg(accent).add_modifier(Modifier::BOLD),
             ),
             // Timestamp
             Span::styled(
-                if ts_str.is_empty() { String::new() } else { format!("  {}", ts_str) },
+                if ts_str.is_empty() { String::new() } else { format!("  {ts_str}") },
                 Style::default().fg(Theme::TEXT_DIM),
             ),
         ]);
@@ -176,7 +178,7 @@ pub fn draw_chat(frame: &mut Frame, area: Rect, state: &crate::app::state::rest:
                     .add_modifier(Modifier::BOLD),
             ),
             Span::styled(
-                format!(" {} ", spinner),
+                format!(" {spinner} "),
                 Style::default().fg(Theme::ROLE_ASSISTANT).add_modifier(Modifier::BOLD),
             ),
             Span::styled(