hive-c0re: serialise the matrix and knowledge sweeps through the job queue

The matrix sweep and the /knowledge pull each had concurrent callers
(#4723 item 4). Two overlapping knowledge pulls fail on .git/index.lock
and the remote-tracking ref lock: 30 of 30 concurrent replays of the
reset/clean/pull sequence in a scratch repo errored, 0 of 10 sequential
ones did. Two overlapping matrix sweeps on a hive with no persisted
Space / chat-room id both miss the by-name lookup and both createRoom
(from reading the code, not reproduced against a homeserver). On every
boot the MatrixSweep DAG node and the main.rs loop's immediate first
call ran at once.

Every sweep now runs as a job node, and each sweep's node holds its own
capacity-1 queue resource (Resource::MatrixSweep,
Resource::KnowledgeTree), the MetaWindow pattern: the scheduler never
starts a second pass of one sweep while the first holds the resource,
and different sweeps still run side by side.

- templates::matrix_sweep / templates::knowledge_pull build the node
  with its resource; boot, the periodic loops and the swarm event all
  use them.
- JobQueue::insert_unless_live folds a submission into a live node of
  the same kind instead of queueing another. Periodic ticks fold into a
  queued or running pass. The swarm knowledge event folds into a queued
  pull only, and queues one behind a running pull, which may have
  fetched before the push.
- The main.rs matrix loop no longer sweeps immediately at startup; the
  boot MatrixSweep node is the startup pass, as KnowledgePull already
  was for knowledge.
- The executors bound each pass (10 min matrix, 5 min knowledge), since
  a hung pass would otherwise hold its resource against every later one,
  and own the sweep-health banners, so every pass reports to them.

Replaces the SweepLock version of this branch, per review.

Refs #4723

hive-c0re/src/job_queue/resource.rs

@@ -31,6 +31,15 @@ pub enum Resource {
     /// The meta-repo mutation window — a global singleton held by any node
     /// that mutates the meta repo, so two meta mutations never interleave.
     MetaWindow,
+    /// The `/knowledge` working tree, held by every `KnowledgePull`. Two
+    /// overlapping `reset` / `clean` / `pull` passes there fail on
+    /// `.git/index.lock` and the remote-tracking ref lock.
+    KnowledgeTree,
+    /// The hive's matrix provisioning, held by every `MatrixSweep`. Two
+    /// overlapping passes on a hive with no persisted Space / chat-room id both
+    /// miss the by-name lookup and both `createRoom`, leaving a duplicate room
+    /// with agents invited to both.
+    MatrixSweep,
 }
 
 /// This resource's name on the generic graph wire.
@@ -45,6 +54,8 @@ impl hive_jobq_wire::WireResource for Resource {
             Resource::BuildSlot => "build-slot".to_owned(),
             Resource::Agent(agent) => format!("agent:{agent}"),
             Resource::MetaWindow => "meta-window".to_owned(),
+            Resource::KnowledgeTree => "knowledge-tree".to_owned(),
+            Resource::MatrixSweep => "matrix-sweep".to_owned(),
         }
     }
 }