feat(#2485): remove vestigial Noop + StartupSweep residuals

Since the boot sweep (#2450) and meta-update cascade (#2476) became
single DAGs that grow subgraphs in-place, nothing constructs the old
fan-out anchors/parents anymore:

- NodeKind::Noop (the old boot_root grouping anchor) — no constructors.
- Template::StartupSweep / Source::StartupSweep (the old fan-out parent
  template + cascade-child source) — replaced by Template::Boot and
  Source::AutoUpdate/MetaUpdate respectively.

Drops the three variants + their as_str arms + the Noop executor arm, and
refreshes the stale fan-out/anchor doc comments (Boot/MetaUpdate/Source
docs, coordinator.md, dashboard.md). Frontend: the queue-kind glyph moves
from the dead startup_sweep to boot (which had none), and the dead
rqe-source-startup_sweep style is dropped.

No behaviour change — pure dead-variant removal.

hive-sh4re/src/jobs.rs

@@ -17,16 +17,13 @@ pub enum Template {
     /// Rebuild one agent's container (prebuild → stop → profile-swap →
     /// reconcile).
     Rebuild,
-    /// Bump meta flake locks; child `Rebuild` DAGs fan out on
-    /// completion for every affected agent.
+    /// Bump meta flake locks; grows a rebuild subgraph per affected
+    /// agent into the same DAG on completion.
     MetaUpdate,
     /// First-deploy spawn (approval-driven).
     Spawn,
     /// Reserved for a future destroy integration.
     Destroy,
-    /// Boot-time config sweep (hyperhive lock bump + stale-agent
-    /// rebuild fan-out).
-    StartupSweep,
     /// Mechanical stop + converge to `wanted = Up` (a restart).
     Restart,
     /// Signal → drain → mechanical stop → converge to `wanted = Up` — a
@@ -45,9 +42,9 @@ pub enum Template {
     /// Bare converge of observed power state to the persisted intent
     /// (boot reconcile).
     Reconcile,
-    /// Boot-time root anchor: a single no-op node that groups this boot's
-    /// `StartupSweep` + per-agent `Reconcile` child DAGs under one tree, so the
-    /// dashboard renders the whole boot as one entry instead of N+1 rows.
+    /// Boot-time config sweep as one DAG: a hyperhive lock bump that grows
+    /// a rebuild subgraph per stale agent, plus a `Reconcile` per drifted
+    /// agent — all in a single DAG (no anchor node, no child DAGs).
     Boot,
 }
 
@@ -59,7 +56,6 @@ impl Template {
             Template::MetaUpdate => "meta_update",
             Template::Spawn => "spawn",
             Template::Destroy => "destroy",
-            Template::StartupSweep => "startup_sweep",
             Template::Restart => "restart",
             Template::GracefulRestart => "graceful_restart",
             Template::PermChange => "perm_change",
@@ -79,12 +75,10 @@ impl Template {
 pub enum Source {
     /// Operator action (dashboard button, CLI, manager tool).
     Manual,
-    /// Cascade child of a `MetaUpdate` DAG's fan-out.
+    /// Meta-update cascade rebuild (grown into the meta-update DAG).
     MetaUpdate,
-    /// Boot-time submission (sweep parent, boot reconciles).
+    /// Boot-time submission (the boot sweep DAG + boot reconciles).
     AutoUpdate,
-    /// Cascade child of a `StartupSweep` DAG's fan-out.
-    StartupSweep,
     /// Crash recovery path (future use).
     CrashRecover,
     /// Operator approved a pending `Approval` row; `approval_id` on
@@ -99,7 +93,6 @@ impl Source {
             Source::Manual => "manual",
             Source::MetaUpdate => "meta_update",
             Source::AutoUpdate => "auto_update",
-            Source::StartupSweep => "startup_sweep",
             Source::CrashRecover => "crash_recover",
             Source::Approval => "approval",
         }