Close Campaign interface audit gaps

src/govoplan_campaign/backend/manifest.py

@@ -527,7 +527,6 @@ manifest = ModuleManifest(
                 order=22,
                 surface_id=REPORTS_SURFACE_ID,
             ),
-            FrontendRoute(path="/templates", component="TemplatesPage", order=90),
         ),
         nav_items=(
             NavItem(
@@ -537,9 +536,6 @@ manifest = ModuleManifest(
                 required_any=CAMPAIGN_MODULE_REQUIRED_ANY,
                 order=20,
             ),
-            NavItem(
-                path="/templates", label="Templates", icon="layout-template", order=90
-            ),
         ),
         view_surfaces=(
             ViewSurface(
@@ -808,7 +804,7 @@ manifest = ModuleManifest(
             id="campaigns.workflow.prepare-validate-and-build",
             title="Prepare, validate, and build a campaign",
             summary="Turn governed recipient, template, attachment, and Mail-profile inputs into exact built messages for review.",
-            body="Prepare each input in its owning surface, resolve every blocking validation issue, and build exact recipient messages before review. Campaign freezes recipient and attachment evidence for the selected version; later source changes do not silently alter that build.",
+            body="Prepare each input in its owning surface, resolve every blocking validation issue, and build exact recipient messages before review. Campaign freezes recipient and attachment evidence for the selected version; later source changes do not silently alter that build. When the Templates module is installed, its single Templates navigation entry owns the reusable library while campaign-specific composition remains in the campaign workspace.",
             layer="configured",
             documentation_types=("user",),
             audience=("campaign_manager", "campaign_author"),
@@ -836,7 +832,7 @@ manifest = ModuleManifest(
                     kind="repository",
                 ),
             ),
-            related_modules=("addresses", "files", "mail"),
+            related_modules=("addresses", "files", "mail", "templates"),
             unlocks=(
                 "A reviewable build whose exact recipient-specific effects can be inspected before delivery.",
             ),

src/govoplan_campaign/backend/routes/attachments.py

@@ -23,6 +23,9 @@ from govoplan_campaign.backend.path_security import (
     assert_server_safe_campaign_paths,
 )
 from govoplan_campaign.backend.campaign.loader import load_campaign_json
+from govoplan_campaign.backend.campaign.mail_profile_boundary import (
+    CampaignMailProfileBoundaryError,
+)
 from govoplan_campaign.backend.attachments.resolver import resolve_campaign_attachments
 from govoplan_campaign.backend.persistence.versions import (
     is_version_final_locked,
@@ -324,7 +327,7 @@ def preview_campaign_attachments(
             include_unmatched=payload.include_unmatched,
             include_unlinked_candidates=payload.include_unlinked_candidates,
         )
-    except CampaignPathSecurityError as exc:
+    except (CampaignPathSecurityError, CampaignMailProfileBoundaryError) as exc:
         raise HTTPException(
             status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, detail=str(exc)
         ) from exc