E2 Phase 1: external-license-resources — xceesd daemon, extres role, EXTERNAL admission

Implements Phase 1 of .kiro/specs/external-license-resources/ (design.md):
externally-reported license pools pushed by a dedicated daemon through the
existing resval pipeline, with EXTERNAL-aware admission arithmetic.

Wire & controller:
- controller.capnp HostRole.extres (@5, appended); xce_join_req accepts it
- extres.c: HostRole_extres join table (endpoint+name, no workermgr slot),
  leave cleanup; join.c/cluster.c dispatch
- opupd.c do_update_resvals: extres branch runs the resource hooks and
  update_resval_list(c, NULL, ...) — host=="" entries route through
  update_val_res' SHARED branch into c->sharedinst; per-entry -EPERM for
  non-shared targets is logged, never fails the list
- worker.c update_val_res: NULL worker only writes SHARED resources
- cluster.c cluster_build_resources: rebuilt on resourceApplyDef (bug-1854)
  — EEXIST-tolerant so definitions added by an activation register on a
  RUNNING controller (bug-1973), and RES_APPLY_CHANGED updates definition
  fields (valtype/ordtype/flags/interval) in place so a corrected config
  heals a stale registration (bug-1974); seed_sharedinst_from_config skips
  EXTERNAL pools (daemon-reported free counts only; seeding would fabricate
  capacity while the daemon is down)

Scheduler:
- core_events.c RESVALS_DELTA: NULL/"" host marks a SHARED value and lands
  in core->sharedInst via dup_val (bug-1585 ownership rule), mirroring
  snapshot_load's host=="" precedent — previously WARN-skipped as unknown
  worker
- resource.c unsatisfy_: EXTERNAL skips the inuse term
  (F >= uncomit + wanted; F is already net of our checkouts)

xceesd (src/esd, new component):
- script collectors polled per source, debounce on unchanged values,
  fail-open stale policy; pushes host=="" shared resvals over xcecli
- reconnect gap fix (bug-1975): with a stable value the debounce pushed
  nothing and reconnects only fire inside a push — after a controller
  restart the daemon sat on a dead connection forever; the main loop now
  forces a full re-push when xcecli_is_connection_broken() (bug-1760
  predicate) latches

Config/mapping:
- resources.yaml: extlic sample (location: [external])
- mapping.py: RESOURCE_FLAG_EXTERNAL (0x10) + location:["external"] mapping;
  xceadmin tests

Tests (TDD, red->green per fix): test_extres_resvals.c (join+resval
pipeline), test_config_resource_reconcile.c +2 (register past EEXIST /
hot-apply changed definition), test_core_events.c +131 lines (shared DELTA
landing), mapping tests. Suites: controller 1358/0, scheduler 100/0,
esd 7/0, lib 1/0; check-no-fork covers src/esd.

Live t1 E2E: config gen=15 push -> xceesd push extlic=4 lands in
sharedinst -> rusage[extlic=3] job RUN; second job PENDs at free=1;
release re-admits it; controller restart -> forced re-push restores the
value and admission resumes. Full precommit job verification passed.

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

src/xceadmin/tests/test_mapping.py

@@ -248,6 +248,42 @@ def test_map_list_section_resourcemap_maps_distributions_and_all_flag(cluster_co
     assert r4.flags == 0
 
 
+def test_map_list_section_resourcemap_external_location_flag(cluster_config):
+    """resourcemap location==["external"] (external-license-resources): the
+    resource carries XCE_RESF_SHARED | XCE_RESF_GLOBAL | XCE_RESF_EXTERNAL
+    (0x08|0x04|0x10) -- cluster-wide pool, but its values come only from the
+    extres daemon's free-count pushes, never from a config distribution or
+    worker reports. A bare ["external"] (no value) also maps definition-only
+    -- the daemon owns the values entirely.
+    """
+    items = [
+        {
+            "name": "verilog_xl",
+            "type": "numeric",
+            "consumable": True,
+            "resourcemap": [{"location": ["external"]}],
+        },
+        {
+            "name": "extlic_valued",
+            "type": "numeric",
+            "resourcemap": [{"location": ["external"], "value": 7}],
+        },
+    ]
+    mapping.map_list_section(_spec_for("resources"), items, cluster_config)
+
+    r0, r1 = cluster_config.resources
+
+    # CONSUMABLE | SHARED | GLOBAL | EXTERNAL
+    assert r0.flags == 0x80 | 0x08 | 0x04 | 0x10
+    assert len(r0.distributions) == 1
+    assert [str(h) for h in r0.distributions[0].hosts] == ["external"]
+
+    # valued variant: same flags, the distribution value still maps (the
+    # controller refuses to seed it -- EXTERNAL skips seed_sharedinst)
+    assert r1.flags == 0x08 | 0x04 | 0x10
+    assert r1.distributions[0].value.u.fvalue == 7.0
+
+
 def test_map_list_section_resourcemap_real_repo_configs(cluster_config):
     """The mapper handles the real src/configs/resources.yaml: every
     resourcemap entry lands as a distribution, and the two [all]+value