refactor: Remove redundant doc comments throughout codebase

Removes module-level doc comments (//! lines) and excessive inline doc
comments that were duplicating information already evident from:
- Function/struct names (self-documenting code)
- Type signatures (the what is clear from types)
- Implementation context (the how is clear from code)

Affected modules:
- cli/* - Removed command descriptions duplicating clap help text
- core/* - Removed module headers and obvious function docs
- documents/* - Removed extractor/regenerator/truncation docs
- embedding/* - Removed pipeline and chunking docs
- gitlab/* - Removed client and transformer docs (kept type definitions)
- ingestion/* - Removed orchestrator and ingestion docs
- search/* - Removed FTS and vector search docs

Philosophy: Code should be self-documenting. Comments should explain
"why" (business decisions, non-obvious constraints) not "what" (which
the code itself shows). This change reduces noise and maintenance burden
while keeping the codebase just as understandable.

Retains comments for:
- Non-obvious business logic
- Important safety invariants
- Complex algorithm explanations
- Public API boundaries where generated docs matter

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/cli/commands/sync_status.rs

@@ -1,5 +1,3 @@
-//! Sync status command - display synchronization state from local database.
-
 use console::style;
 use rusqlite::Connection;
 use serde::Serialize;
@@ -13,7 +11,6 @@ use crate::core::time::{format_full_datetime, ms_to_iso};
 
 const RECENT_RUNS_LIMIT: usize = 10;
 
-/// Sync run information.
 #[derive(Debug)]
 pub struct SyncRunInfo {
     pub id: i64,
@@ -28,7 +25,6 @@ pub struct SyncRunInfo {
     pub stages: Option<Vec<StageTiming>>,
 }
 
-/// Cursor position information.
 #[derive(Debug)]
 pub struct CursorInfo {
     pub project_path: String,
@@ -37,7 +33,6 @@ pub struct CursorInfo {
     pub tie_breaker_id: Option<i64>,
 }
 
-/// Data summary counts.
 #[derive(Debug)]
 pub struct DataSummary {
     pub issue_count: i64,
@@ -47,7 +42,6 @@ pub struct DataSummary {
     pub system_note_count: i64,
 }
 
-/// Complete sync status result.
 #[derive(Debug)]
 pub struct SyncStatusResult {
     pub runs: Vec<SyncRunInfo>,
@@ -55,7 +49,6 @@ pub struct SyncStatusResult {
     pub summary: DataSummary,
 }
 
-/// Run the sync-status command.
 pub fn run_sync_status(config: &Config) -> Result<SyncStatusResult> {
     let db_path = get_db_path(config.storage.db_path.as_deref());
     let conn = create_connection(&db_path)?;
@@ -71,7 +64,6 @@ pub fn run_sync_status(config: &Config) -> Result<SyncStatusResult> {
     })
 }
 
-/// Get the most recent sync runs.
 fn get_recent_sync_runs(conn: &Connection, limit: usize) -> Result<Vec<SyncRunInfo>> {
     let mut stmt = conn.prepare(
         "SELECT id, started_at, finished_at, status, command, error,
@@ -105,7 +97,6 @@ fn get_recent_sync_runs(conn: &Connection, limit: usize) -> Result<Vec<SyncRunIn
     Ok(runs?)
 }
 
-/// Get cursor positions for all projects/resource types.
 fn get_cursor_positions(conn: &Connection) -> Result<Vec<CursorInfo>> {
     let mut stmt = conn.prepare(
         "SELECT p.path_with_namespace, sc.resource_type, sc.updated_at_cursor, sc.tie_breaker_id
@@ -128,7 +119,6 @@ fn get_cursor_positions(conn: &Connection) -> Result<Vec<CursorInfo>> {
     Ok(cursors?)
 }
 
-/// Get data summary counts.
 fn get_data_summary(conn: &Connection) -> Result<DataSummary> {
     let issue_count: i64 = conn
         .query_row("SELECT COUNT(*) FROM issues", [], |row| row.get(0))
@@ -159,7 +149,6 @@ fn get_data_summary(conn: &Connection) -> Result<DataSummary> {
     })
 }
 
-/// Format duration in milliseconds to human-readable string.
 fn format_duration(ms: i64) -> String {
     let seconds = ms / 1000;
     let minutes = seconds / 60;
@@ -176,7 +165,6 @@ fn format_duration(ms: i64) -> String {
     }
 }
 
-/// Format number with thousands separators.
 fn format_number(n: i64) -> String {
     let is_negative = n < 0;
     let abs_n = n.unsigned_abs();
@@ -198,10 +186,6 @@ fn format_number(n: i64) -> String {
     result
 }
 
-// ============================================================================
-// JSON output structures for robot mode
-// ============================================================================
-
 #[derive(Serialize)]
 struct SyncStatusJsonOutput {
     ok: bool,
@@ -254,7 +238,6 @@ struct SummaryJsonInfo {
     system_notes: i64,
 }
 
-/// Print sync status as JSON (robot mode).
 pub fn print_sync_status_json(result: &SyncStatusResult) {
     let runs = result
         .runs
@@ -306,13 +289,7 @@ pub fn print_sync_status_json(result: &SyncStatusResult) {
     println!("{}", serde_json::to_string(&output).unwrap());
 }
 
-// ============================================================================
-// Human-readable output
-// ============================================================================
-
-/// Print sync status result.
 pub fn print_sync_status(result: &SyncStatusResult) {
-    // Recent Runs section
     println!("{}", style("Recent Sync Runs").bold().underlined());
     println!();
 
@@ -330,7 +307,6 @@ pub fn print_sync_status(result: &SyncStatusResult) {
 
     println!();
 
-    // Cursor Positions section
     println!("{}", style("Cursor Positions").bold().underlined());
     println!();
 
@@ -361,7 +337,6 @@ pub fn print_sync_status(result: &SyncStatusResult) {
 
     println!();
 
-    // Data Summary section
     println!("{}", style("Data Summary").bold().underlined());
     println!();
 
@@ -390,7 +365,6 @@ pub fn print_sync_status(result: &SyncStatusResult) {
     );
 }
 
-/// Print a single run as a compact one-liner.
 fn print_run_line(run: &SyncRunInfo) {
     let status_styled = match run.status.as_str() {
         "succeeded" => style(&run.status).green(),