Add photo management for models and employees; fix stale detail navigation

Model photos: upload/replace/delete on /api/models/<id>/image (admin),
stored under instance/modelimages/ with a public serve route; thumbnail
plus Upload/Replace/Remove controls in the Models settings modal; the
URL field remains as a manual alternative.

Employee photos, mode-aware: self-hosted directory employees get
upload/replace/delete (photo-<sso> under instance/employeephotos/,
employees plugin migration 0002); external directory mode passes the
HR-supplied picture URL through read-only (writes 409). One resolver
feeds both consumers - the shopfloor recognition/recert kiosk cards and
the employee detail hero - in either mode.

Navigation fix: router-view is keyed on route path, so following a
relationship link between two assets of the same type (machine ->
dualpath machine) reloads the page instead of showing stale content;
query-only URL changes still avoid a remount.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -12,6 +12,19 @@ ADR-007 and ADR-002.
 
 ### Added
 
+- Vendor-model photo management. New admin-gated core endpoints
+  `POST /api/models/<modelid>/image` (multipart `file`, png/jpg/jpeg/gif/webp/svg,
+  one image per model, replace semantics) and
+  `DELETE /api/models/<modelid>/image`, plus the public
+  `GET /api/models/image/<filename>` serve route. Uploads land in
+  `instance/modelimages/` (survives upgrades, backed up with the rest of
+  `instance/`) and set `models.imageurl` to the served URL; the manual Image URL
+  field still accepts external URLs and the shipped `/images/models/*` assets
+  (upload is additive). Delete only removes files we own under the instance dir.
+  The Models settings page grows a thumbnail, Upload/Replace, and Remove
+  controls in the edit modal. Asset hero images (e.g. the machine badge) read
+  `imageurl` unchanged, so uploaded photos render with no consumer changes.
+
 - Application support teams with contacts, replacing the legacy
   supportteams/appowners pair. New core `supportteamcontacts` table (multiple
   named contacts per team, ordered by `sortorder`); `supportteams` keeps
@@ -51,6 +64,21 @@ ADR-007 and ADR-002.
     no-target list with dispositions, a worked idempotent Python importer, and
     row-count parity checks.
 
+### Fixed
+
+- Asset relationships card no longer lists a symmetric peer twice. Relationship
+  types gain `relationshiptypes.isdirectional` (migration
+  `7d19_relationshiptype_directional`; seeded false for the connection-like
+  types Dualpath, connectedto, Cluster Member, Serial Cable, Direct Ethernet,
+  USB, WiFi, true for controls/Controlled By/Backup For/Master-Slave/partof/
+  defaultprinter). The card now collapses every stored direction row of a
+  symmetric type into one direction-blind "Connected" entry per peer (deleting
+  it removes all collapsed rows), while directional types drop the
+  Outgoing/Incoming headers for inline `Type -> peer` / `<- Type from peer`
+  phrasing. The type CRUD and the per-asset relationships endpoint carry
+  `isdirectional`; the Relationship Types settings page gains a Directional
+  toggle.
+
 ## [0.6.0] - 2026-07-11
 
 ### Added