fix(timeline): report true total_events in robot JSON meta

The robot JSON envelope's meta.total_events field was incorrectly
reporting events.len() (the post-limit count), making it identical
to meta.showing. This defeated the purpose of having both fields.

Changes across the pipeline to fix this:

- collect_events now returns (Vec<TimelineEvent>, usize) where the
  second element is the total event count before truncation
- TimelineResult gains a total_events_before_limit field (serde-skipped)
  so the value flows cleanly from collect through to the renderer
- main.rs passes the real total instead of the events.len() workaround

Additional cleanup in this pass:

- Derive PartialEq/Eq/PartialOrd/Ord on TimelineEventType, replacing
  the hand-rolled event_type_discriminant() function. Variant declaration
  order now defines sort tiebreak, documented in a doc comment.
- Validate --since input with a proper LoreError::Other instead of
  silently treating invalid values as None
- Fix ANSI-aware tag column padding with console::pad_str (colored tags
  like "[merged]" were misaligned because ANSI escapes consumed width)
- Remove dead print_timeline_json and infer_max_depth functions that
  were superseded by print_timeline_json_with_meta

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/cli/commands/timeline.rs

@@ -1,9 +1,9 @@
-use console::style;
+use console::{Alignment, pad_str, style};
 use serde::Serialize;
 
 use crate::Config;
 use crate::core::db::create_connection;
-use crate::core::error::Result;
+use crate::core::error::{LoreError, Result};
 use crate::core::paths::get_db_path;
 use crate::core::project::resolve_project;
 use crate::core::time::{ms_to_iso, parse_since};
@@ -38,7 +38,17 @@ pub fn run_timeline(config: &Config, params: &TimelineParams) -> Result<Timeline
         .map(|p| resolve_project(&conn, p))
         .transpose()?;
 
-    let since_ms = params.since.as_deref().and_then(parse_since);
+    let since_ms = params
+        .since
+        .as_deref()
+        .map(|s| {
+            parse_since(s).ok_or_else(|| {
+                LoreError::Other(format!(
+                    "Invalid --since value: '{s}'. Use a duration (7d, 2w, 6m) or date (2024-01-15)"
+                ))
+            })
+        })
+        .transpose()?;
 
     // Stage 1+2: SEED + HYDRATE
     let seed_result = seed_timeline(
@@ -60,7 +70,7 @@ pub fn run_timeline(config: &Config, params: &TimelineParams) -> Result<Timeline
     )?;
 
     // Stage 4: COLLECT
-    let events = collect_events(
+    let (events, total_before_limit) = collect_events(
         &conn,
         &seed_result.seed_entities,
         &expand_result.expanded_entities,
@@ -72,6 +82,7 @@ pub fn run_timeline(config: &Config, params: &TimelineParams) -> Result<Timeline
     Ok(TimelineResult {
         query: params.query.clone(),
         events,
+        total_events_before_limit: total_before_limit,
         seed_entities: seed_result.seed_entities,
         expanded_entities: expand_result.expanded_entities,
         unresolved_references: expand_result.unresolved_references,
@@ -125,7 +136,8 @@ fn print_timeline_event(event: &TimelineEvent) {
     let expanded_marker = if event.is_seed { "" } else { " [expanded]" };
 
     let summary = truncate_summary(&event.summary, 50);
-    println!("{date}  {tag:12}  {entity_ref:7}  {summary:50}  {actor}{expanded_marker}");
+    let tag_padded = pad_str(&tag, 12, Alignment::Left, None);
+    println!("{date}  {tag_padded}  {entity_ref:7}  {summary:50}  {actor}{expanded_marker}");
 
     // Show snippet for evidence notes
     if let TimelineEventType::NoteEvidence { snippet, .. } = &event.event_type
@@ -235,29 +247,6 @@ fn wrap_snippet(text: &str, width: usize) -> Vec<String> {
 // ─── Robot JSON output ───────────────────────────────────────────────────────
 
 /// Render timeline as robot-mode JSON in {ok, data, meta} envelope.
-pub fn print_timeline_json(result: &TimelineResult, total_events_before_limit: usize) {
-    let output = TimelineJsonEnvelope {
-        ok: true,
-        data: TimelineDataJson::from_result(result),
-        meta: TimelineMetaJson {
-            search_mode: "lexical".to_owned(),
-            expansion_depth: infer_max_depth(&result.expanded_entities),
-            expand_mentions: false, // caller should pass this, but we infer from data
-            total_entities: result.seed_entities.len() + result.expanded_entities.len(),
-            total_events: total_events_before_limit,
-            evidence_notes_included: count_evidence_notes(&result.events),
-            unresolved_references: result.unresolved_references.len(),
-            showing: result.events.len(),
-        },
-    };
-
-    match serde_json::to_string(&output) {
-        Ok(json) => println!("{json}"),
-        Err(e) => eprintln!("Error serializing timeline JSON: {e}"),
-    }
-}
-
-/// Extended version that accepts explicit meta values from the caller.
 pub fn print_timeline_json_with_meta(
     result: &TimelineResult,
     total_events_before_limit: usize,
@@ -482,10 +471,6 @@ struct TimelineMetaJson {
     showing: usize,
 }
 
-fn infer_max_depth(expanded: &[ExpandedEntityRef]) -> u32 {
-    expanded.iter().map(|e| e.depth).max().unwrap_or(0)
-}
-
 fn count_evidence_notes(events: &[TimelineEvent]) -> usize {
     events
         .iter()