feat(sync): Instrument pipeline with tracing spans, run_id correlation, and metrics

Add end-to-end observability to the sync and ingest pipelines:

Sync command:
- Generate UUID-based run_id for each sync invocation, propagated through
  all child spans for log correlation across stages
- Accept MetricsLayer reference to extract hierarchical StageTiming data
  after pipeline completion for robot-mode performance output
- Record sync runs in DB via SyncRunRecorder (start/succeed/fail lifecycle)
- Wrap entire sync execution in a root tracing span with run_id field

Ingest command:
- Wrap run_ingest in an instrumented root span with run_id and resource_type
- Add project path prefix to discussion progress bars for multi-project clarity
- Reset resource_events_synced_for_updated_at on --full re-sync

Sync status:
- Expand from single last_run to configurable recent runs list (default 10)
- Parse and expose StageTiming metrics from stored metrics_json
- Add run_id, total_items_processed, total_errors to SyncRunInfo
- Add mr_count to DataSummary for complete entity coverage

Orchestrator:
- Add #[instrument] with structured fields to issue and MR ingestion functions
- Record items_processed, items_skipped, errors on span close for MetricsLayer
- Emit granular progress events (IssuesFetchStarted, IssuesFetchComplete)
- Pass project_id through to drain_resource_events for scoped job claiming

Document regenerator and embedding pipeline:
- Add #[instrument] spans with items_processed, items_skipped, errors fields
- Record final counts on span close for metrics extraction

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

src/cli/commands/ingest.rs

@@ -5,6 +5,8 @@ use indicatif::{ProgressBar, ProgressStyle};
 use rusqlite::Connection;
 use serde::Serialize;
 
+use tracing::Instrument;
+
 use crate::Config;
 use crate::core::db::create_connection;
 use crate::core::error::{LoreError, Result};
@@ -111,6 +113,24 @@ pub async fn run_ingest(
     force: bool,
     full: bool,
     display: IngestDisplay,
+) -> Result<IngestResult> {
+    let run_id = uuid::Uuid::new_v4().simple().to_string();
+    let run_id = &run_id[..8];
+    let span = tracing::info_span!("ingest", %run_id, %resource_type);
+
+    run_ingest_inner(config, resource_type, project_filter, force, full, display)
+        .instrument(span)
+        .await
+}
+
+/// Inner implementation of run_ingest, instrumented with a root span.
+async fn run_ingest_inner(
+    config: &Config,
+    resource_type: &str,
+    project_filter: Option<&str>,
+    force: bool,
+    full: bool,
+    display: IngestDisplay,
 ) -> Result<IngestResult> {
     // Validate resource type early
     if resource_type != "issues" && resource_type != "mrs" {
@@ -162,15 +182,15 @@ pub async fn run_ingest(
         }
         for (local_project_id, _, path) in &projects {
             if resource_type == "issues" {
-                // Reset issue discussion watermarks first so discussions get re-synced
+                // Reset issue discussion and resource event watermarks so everything gets re-synced
                 conn.execute(
-                    "UPDATE issues SET discussions_synced_for_updated_at = NULL WHERE project_id = ?",
+                    "UPDATE issues SET discussions_synced_for_updated_at = NULL, resource_events_synced_for_updated_at = NULL WHERE project_id = ?",
                     [*local_project_id],
                 )?;
             } else if resource_type == "mrs" {
-                // Reset MR discussion watermarks
+                // Reset MR discussion and resource event watermarks
                 conn.execute(
-                    "UPDATE merge_requests SET discussions_synced_for_updated_at = NULL WHERE project_id = ?",
+                    "UPDATE merge_requests SET discussions_synced_for_updated_at = NULL, resource_events_synced_for_updated_at = NULL WHERE project_id = ?",
                     [*local_project_id],
                 )?;
             }
@@ -255,11 +275,12 @@ pub async fn run_ingest(
                     b.set_style(
                         ProgressStyle::default_bar()
                             .template(
-                                "    {spinner:.blue} Syncing discussions [{bar:30.cyan/dim}] {pos}/{len}",
+                                "    {spinner:.blue} {prefix:.cyan} Syncing discussions [{bar:30.cyan/dim}] {pos}/{len}",
                             )
                             .unwrap()
                             .progress_chars("=> "),
                     );
+                    b.set_prefix(path.clone());
                     b
                 };
 
@@ -296,7 +317,7 @@ pub async fn run_ingest(
                             disc_bar_clone.set_length(total as u64);
                             disc_bar_clone.set_style(
                                 ProgressStyle::default_bar()
-                                    .template("    {spinner:.blue} Fetching resource events [{bar:30.cyan/dim}] {pos}/{len}")
+                                    .template("    {spinner:.blue} {prefix:.cyan} Fetching resource events [{bar:30.cyan/dim}] {pos}/{len}")
                                     .unwrap()
                                     .progress_chars("=> "),
                             );