Stop the collector being able to set a printer assignment

The printer feature rests on one rule: a collector report is OBSERVED state and
never ASSIGNED state. If a drifted bay's own state can become what it is told to
install, enforcement stops meaning anything, because a bay that installed the
wrong printer makes itself right simply by reporting it.

_sync_printer_links broke that rule. It ran on every collector PC push and, when
the payload carried defaultprinter or printers, wrote defaultprinter and
connectedto rows from the report - defaultprinter being one of the two types
_reconcile_edges is meant to own alone, from authenticated routes a human calls.

It was recorded as dormant. It was not. The collector schema ADVERTISED both
keys and the example client in COLLECTOR-INTEGRATION.md set
$payload['defaultprinter'], so the documentation was recruiting callers for it -
while the same document, under "Observed is not assigned", promised that nothing
on this path writes a usesprinter or defaultprinter row. The document
contradicted itself and the code followed the wrong half. Nothing in the fleet
armed it, because the first-party reporter never sent those fields, but any
third-party client written from the docs would have.

Retired the function, its _sync_one helper and the now-unused
PRINTER_LINK_ORIGIN label, and removed both keys from the schema.

IGNORED, NOT REJECTED. Unknown payload keys are not validated, so a client
written against the old docs keeps pushing successfully and only its printer
keys stop doing anything. The response warns, naming the keys and pointing at
POST /api/collector/printers for reporting queues and seed-from-observed for
adopting them. Dropping them in silence would leave an integrator believing
assignments were still being written, which is a worse failure than the one
being fixed.

The docs were the larger half of this. The schema table rows are gone, the
"PC -> printer relationship sync" section is replaced by a note saying what
happens now to anyone still sending the keys, and the example client no longer
enumerates Win32_Printer at all - it points at Report-PrintersToShopDB.ps1,
which posts to the observed endpoint and posts NOTHING on a failed enumeration,
since an empty list would erase the host's rows.

test_collector_printers.py pinned the old behaviour, so it now pins the
opposite: the keys create no relationships, the push still succeeds and says
why, a payload without them stays quiet, a human-made default survives a report
naming a different printer, and the schema no longer offers the keys.

tests/test_core/test_collector_printers.py

@@ -1,11 +1,19 @@
-"""Tests for the computers collector PC->printer relationship sync.
+"""The computers collector must NEVER write a printer assignment.
 
-A collector payload carrying defaultprinter/printers creates AssetRelationship
-rows linking the PC asset to the resolved printer assets ('defaultprinter' for
-the default, 'connectedto' for the rest). Stale collector links archive on
-re-report; manual links survive; unresolved identifiers warn without failing.
+This file used to pin the opposite: `_sync_printer_links` turned a payload's
+`defaultprinter`/`printers` into AssetRelationship rows. That contradicted the
+rule the printer feature rests on - ASSIGNED and OBSERVED never mix - because a
+bay that installed the wrong printer would have made itself right just by
+reporting it.
+
+It was not dormant. The collector schema advertised both keys and
+COLLECTOR-INTEGRATION.md's example client set `defaultprinter`, while another
+page of the same document promised nothing on this path writes an assignment
+row. Retired 2026-08-24; these tests are the guard that it stays retired.
+
+Observed queues have their own path (POST /api/collector/printers) and become
+assignments only when a person asks, via seed-from-observed.
 """
-
 import pytest
 
 from shopdb.core.models import (
@@ -81,119 +89,75 @@ def _active_links(db, pcid):
         sourceassetid=pcid, isactive=True).all()
 
 
-def test_creates_default_and_connected_links(client, db, collector_key, scene):
-    """Default -> defaultprinter, others -> connectedto, resolved by three id forms."""
-    resp = _post(client, {
-        'hostname': 'WJPC-P1',
-        'defaultprinter': 'HP-Materials',          # windowsname
-        'printers': ['prn-front.wjs.local', '10.1.2.3'],  # hostname, IP
-    })
-    assert resp.status_code == 200, resp.get_json()
-    data = resp.get_json()['data']
-    assert data['printerlinkcount'] == 3
-    assert not data['warnings']
-
-    pc = _pc_asset(db)
-    links = {(r.targetassetid, r.relationshiptype.relationshiptype)
-             for r in _active_links(db, pc.assetid)}
-    assert (scene['a'].assetid, 'defaultprinter') in links
-    assert (scene['b'].assetid, 'connectedto') in links
-    assert (scene['c'].assetid, 'connectedto') in links
-
-
-def test_unresolved_identifier_warns_not_fails(client, db, collector_key, scene):
-    """An unknown printer identifier is a warning, the rest still link."""
-    resp = _post(client, {
-        'hostname': 'WJPC-P2',
+def test_printer_keys_create_no_relationships(client, db, collector_key, scene):
+    """The reported case, inverted: sending them must change nothing."""
+    response = _post(client, {
+        'hostname': 'BAY-3105-PC',
         'defaultprinter': 'HP-Materials',
-        'printers': ['does-not-exist'],
+        'printers': ['HP-Materials', 'prn-front.wjs.local', '10.1.2.3'],
     })
-    assert resp.status_code == 200
-    data = resp.get_json()['data']
-    assert any('unresolved printer: does-not-exist' in w
-               for w in data['warnings'])
-    pc = _pc_asset(db)
-    assert data['printerlinkcount'] == 1
-    assert len(_active_links(db, pc.assetid)) == 1
+    assert response.status_code in (200, 201), response.get_json()
+
+    pcid = _pc_asset(db).assetid
+    assert _active_links(db, pcid) == [], (
+        'a collector report wrote printer relationships')
 
 
-def test_idempotent_no_duplicates(client, db, collector_key, scene):
-    """Re-report the same set: no new rows, still one link per printer."""
-    payload = {'hostname': 'WJPC-P3', 'defaultprinter': 'HP-Materials',
-               'printers': ['Zebra-Ship']}
-    assert _post(client, payload).status_code == 200
-    assert _post(client, payload).status_code == 200
+def test_the_push_still_succeeds_and_says_why(client, db, collector_key, scene):
+    """Warn, do not reject.
 
-    pc = _pc_asset(db)
-    all_rows = AssetRelationship.query.filter_by(sourceassetid=pc.assetid).all()
-    assert len(all_rows) == 2  # one default + one connected, no dupes
-    assert all(r.isactive for r in all_rows)
+    Unknown keys are not validated, so a client written against the old docs
+    keeps pushing successfully - only its printer keys stop doing anything.
+    Silently dropping them would leave an integrator believing assignments were
+    still being written, which is worse than the original bug.
+    """
+    response = _post(client, {
+        'hostname': 'BAY-3105-PC',
+        'defaultprinter': 'HP-Materials',
+    })
+    assert response.status_code in (200, 201)
+    warnings = ' '.join(response.get_json()['data']['warnings']).lower()
+    assert 'defaultprinter' in warnings
+    assert 'seed-from-observed' in warnings, (
+        'the warning should say where assignment actually comes from')
 
 
-def test_dropped_printer_is_archived(client, db, collector_key, scene):
-    """A printer that stops being reported loses its collector link."""
-    _post(client, {'hostname': 'WJPC-P4', 'defaultprinter': 'HP-Materials',
-                   'printers': ['Zebra-Ship']})
-    pc = _pc_asset(db)
-    assert len(_active_links(db, pc.assetid)) == 2
-
-    # Re-report without Zebra-Ship.
-    _post(client, {'hostname': 'WJPC-P4', 'defaultprinter': 'HP-Materials',
-                   'printers': []})
-    active = _active_links(db, pc.assetid)
-    assert len(active) == 1
-    assert active[0].targetassetid == scene['a'].assetid
-    # the dropped row still exists but is inactive
-    zebra = AssetRelationship.query.filter_by(
-        sourceassetid=pc.assetid, targetassetid=scene['c'].assetid).first()
-    assert zebra is not None and zebra.isactive is False
+def test_a_payload_without_printer_keys_warns_about_nothing(
+        client, db, collector_key, scene):
+    """The normal case must stay quiet - this is every push in the fleet."""
+    response = _post(client, {'hostname': 'BAY-3105-PC'})
+    assert response.status_code in (200, 201)
+    warnings = ' '.join(response.get_json()['data']['warnings']).lower()
+    assert 'printer' not in warnings
 
 
-def test_default_change_archives_old_default(client, db, collector_key, scene):
-    """Changing the default printer archives the previous defaultprinter link."""
-    _post(client, {'hostname': 'WJPC-P5', 'defaultprinter': 'HP-Materials'})
-    pc = _pc_asset(db)
-    _post(client, {'hostname': 'WJPC-P5', 'defaultprinter': 'prn-front.wjs.local'})
-
-    active = _active_links(db, pc.assetid)
-    assert len(active) == 1
-    assert active[0].targetassetid == scene['b'].assetid
-    assert active[0].relationshiptype.relationshiptype == 'defaultprinter'
-
-
-def test_manual_link_survives_collector_sync(client, db, collector_key, scene):
-    """A manually-created link (no collector label) is never archived."""
-    # PC created first via a bare report.
-    _post(client, {'hostname': 'WJPC-P6', 'defaultprinter': 'HP-Materials',
-                   'printers': ['Zebra-Ship']})
-    pc = _pc_asset(db)
-
-    # Manual connectedto link PC -> printer B (label stays NULL).
+def test_a_manual_assignment_survives_a_report_that_names_printers(
+        client, db, collector_key, scene):
+    """The row a person made is the one that matters, and it stays untouched."""
+    _post(client, {'hostname': 'BAY-3105-PC'})
+    pcasset = _pc_asset(db)
     manual = AssetRelationship(
-        sourceassetid=pc.assetid, targetassetid=scene['b'].assetid,
-        relationshiptypeid=scene['ct_type'].relationshiptypeid, notes='by hand')
+        sourceassetid=pcasset.assetid, targetassetid=scene['a'].assetid,
+        relationshiptypeid=scene['dp_type'].relationshiptypeid)
     db.session.add(manual)
     db.session.commit()
-    manual_id = manual.relationshipid
 
-    # Re-report dropping Zebra-Ship and never mentioning printer B.
-    _post(client, {'hostname': 'WJPC-P6', 'defaultprinter': 'HP-Materials',
-                   'printers': []})
+    _post(client, {
+        'hostname': 'BAY-3105-PC',
+        'defaultprinter': 'prn-front.wjs.local',   # a DIFFERENT printer
+        'printers': ['prn-front.wjs.local'],
+    })
 
-    surviving = db.session.get(AssetRelationship, manual_id)
-    assert surviving.isactive is True   # manual link untouched
-    # Zebra (collector) archived.
-    zebra = AssetRelationship.query.filter_by(
-        sourceassetid=pc.assetid, targetassetid=scene['c'].assetid).first()
-    assert zebra.isactive is False
+    links = _active_links(db, pcasset.assetid)
+    assert len(links) == 1
+    assert links[0].targetassetid == scene['a'].assetid, (
+        'the report retargeted a human-made default printer')
 
 
-def test_no_printer_keys_leaves_links_untouched(client, db, collector_key, scene):
-    """A report with no printer keys does not archive existing links."""
-    _post(client, {'hostname': 'WJPC-P7', 'defaultprinter': 'HP-Materials'})
-    pc = _pc_asset(db)
-    assert len(_active_links(db, pc.assetid)) == 1
+def test_the_retired_keys_are_gone_from_the_collector_schema(app):
+    """The schema advertised them, which is how integrators found them."""
+    from plugins.computers.plugin import ComputersPlugin
 
-    # A plain update (no defaultprinter, no printers key) must not archive.
-    _post(client, {'hostname': 'WJPC-P7', 'currentuser': 'alice'})
-    assert len(_active_links(db, pc.assetid)) == 1
+    fields = ComputersPlugin().get_collector_schema()['fields']
+    assert 'defaultprinter' not in fields
+    assert 'printers' not in fields