Fix build warnings across workspace

- Remove redundant token fields from StreamEvent::Finished (data
  already delivered via Usage event)
- Remove dead hotkey_adjust_sampling, MAX_HISTORY, now()
- Fix unused variable warnings (delta, log)
- Suppress deserialization-only field warnings (jsonrpc, role)
- Make start_stream/chat_completion_stream_temp pub(crate)
- Remove unnecessary pub(crate) re-export of internal types

Remaining warnings are TODO items: SkipIndex (scoring not wired),
notify (MCP notifications not wired).

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/mind/identity.rs

@@ -71,7 +71,7 @@ fn find_context_files(cwd: &Path, prompt_file: &str) -> Vec<PathBuf> {
 ///   2. Project dir (if set)
 ///   3. Global (~/.consciousness/)
 /// For journal source, loads recent journal entries.
-fn load_memory_files(cwd: &Path, memory_project: Option<&Path>, context_groups: &[ContextGroup]) -> Vec<(String, String)> {
+fn load_memory_files(memory_project: Option<&Path>, context_groups: &[ContextGroup]) -> Vec<(String, String)> {
     let home = match dirs::home_dir() {
         Some(h) => h,
         None => return Vec::new(),
@@ -178,7 +178,7 @@ pub fn assemble_context_message(cwd: &Path, prompt_file: &str, memory_project: O
         }
     }
 
-    let memories = load_memory_files(cwd, memory_project, context_groups);
+    let memories = load_memory_files(memory_project, context_groups);
     let memory_count = memories.len();
     for (name, content) in memories {
         parts.push((name, content));