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/embed.rs

@@ -1,5 +1,3 @@
-//! Embed command: generate vector embeddings for documents via Ollama.
-
 use console::style;
 use serde::Serialize;
 
@@ -10,7 +8,6 @@ use crate::core::paths::get_db_path;
 use crate::embedding::ollama::{OllamaClient, OllamaConfig};
 use crate::embedding::pipeline::embed_documents;
 
-/// Result of the embed command.
 #[derive(Debug, Default, Serialize)]
 pub struct EmbedCommandResult {
     pub embedded: usize,
@@ -18,9 +15,6 @@ pub struct EmbedCommandResult {
     pub skipped: usize,
 }
 
-/// Run the embed command.
-///
-/// `progress_callback` reports `(processed, total)` as documents are embedded.
 pub async fn run_embed(
     config: &Config,
     full: bool,
@@ -30,7 +24,6 @@ pub async fn run_embed(
     let db_path = get_db_path(config.storage.db_path.as_deref());
     let conn = create_connection(&db_path)?;
 
-    // Build Ollama config from user settings
     let ollama_config = OllamaConfig {
         base_url: config.embedding.base_url.clone(),
         model: config.embedding.model.clone(),
@@ -38,13 +31,9 @@ pub async fn run_embed(
     };
     let client = OllamaClient::new(ollama_config);
 
-    // Health check — fail fast if Ollama is down or model missing
     client.health_check().await?;
 
     if full {
-        // Clear ALL embeddings and metadata atomically for a complete re-embed.
-        // Wrapped in a transaction so a crash between the two DELETEs can't
-        // leave orphaned data.
         conn.execute_batch(
             "BEGIN;
              DELETE FROM embedding_metadata;
@@ -52,7 +41,6 @@ pub async fn run_embed(
              COMMIT;",
         )?;
     } else if retry_failed {
-        // Clear errors so they become pending again
         conn.execute(
             "UPDATE embedding_metadata SET last_error = NULL, attempt_count = 0
              WHERE last_error IS NOT NULL",
@@ -70,7 +58,6 @@ pub async fn run_embed(
     })
 }
 
-/// Print human-readable output.
 pub fn print_embed(result: &EmbedCommandResult) {
     println!("{} Embedding complete", style("done").green().bold(),);
     println!("  Embedded: {}", result.embedded);
@@ -82,14 +69,12 @@ pub fn print_embed(result: &EmbedCommandResult) {
     }
 }
 
-/// JSON output.
 #[derive(Serialize)]
 struct EmbedJsonOutput<'a> {
     ok: bool,
     data: &'a EmbedCommandResult,
 }
 
-/// Print JSON robot-mode output.
 pub fn print_embed_json(result: &EmbedCommandResult) {
     let output = EmbedJsonOutput {
         ok: true,