feat(timeline): wire up lore timeline command with human + robot renderers

Complete Gate 3 by implementing the final three beads:
- bd-2f2: Human output renderer with colored event tags, entity refs,
  evidence snippets, and expansion summary footer
- bd-dty: Robot JSON output with {ok,data,meta} envelope, ISO timestamps,
  nested via provenance, and per-event-type details objects
- bd-1nf: CLI wiring with TimelineArgs (9 flags), Commands::Timeline
  variant, handle_timeline handler, VALID_COMMANDS entry, and robot-docs
  manifest with temporal_intelligence workflow

All 7 Gate 3 children now closed. Pipeline: SEED -> HYDRATE -> EXPAND ->
COLLECT -> RENDER fully operational.

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

src/cli/mod.rs

@@ -179,6 +179,9 @@ pub enum Commands {
         shell: String,
     },
 
+    /// Show a chronological timeline of events matching a query
+    Timeline(TimelineArgs),
+
     #[command(hide = true)]
     List {
         #[arg(value_parser = ["issues", "mrs"])]
@@ -596,6 +599,57 @@ pub struct EmbedArgs {
     pub no_retry_failed: bool,
 }
 
+#[derive(Parser)]
+pub struct TimelineArgs {
+    /// Search query (keywords to find in issues, MRs, and discussions)
+    pub query: String,
+
+    /// Scope to a specific project (fuzzy match)
+    #[arg(short = 'p', long, help_heading = "Filters")]
+    pub project: Option<String>,
+
+    /// Only show events after this date (e.g. "6m", "2w", "2024-01-01")
+    #[arg(long, help_heading = "Filters")]
+    pub since: Option<String>,
+
+    /// Cross-reference expansion depth (0 = no expansion)
+    #[arg(long, default_value = "1", help_heading = "Expansion")]
+    pub depth: u32,
+
+    /// Also follow 'mentioned' edges during expansion (high fan-out)
+    #[arg(long = "expand-mentions", help_heading = "Expansion")]
+    pub expand_mentions: bool,
+
+    /// Maximum number of events to display
+    #[arg(
+        short = 'n',
+        long = "limit",
+        default_value = "100",
+        help_heading = "Output"
+    )]
+    pub limit: usize,
+
+    /// Maximum seed entities from search
+    #[arg(long = "max-seeds", default_value = "10", help_heading = "Expansion")]
+    pub max_seeds: usize,
+
+    /// Maximum expanded entities via cross-references
+    #[arg(
+        long = "max-entities",
+        default_value = "50",
+        help_heading = "Expansion"
+    )]
+    pub max_entities: usize,
+
+    /// Maximum evidence notes included
+    #[arg(
+        long = "max-evidence",
+        default_value = "10",
+        help_heading = "Expansion"
+    )]
+    pub max_evidence: usize,
+}
+
 #[derive(Parser)]
 pub struct CountArgs {
     /// Entity type to count (issues, mrs, discussions, notes, events)