fix(api): normalize trailing slashes — no slash on param routes

Rule: trailing slash only on collection roots (/). Any route containing
a path parameter {…} uses no trailing slash. Applies across all routers,
scripts, Makefile, and tests. Fixes 307-redirect fragility on POST/PATCH
from naive clients (curl, Codex HTTP calls).

Also adds POST /repos/{slug}/sync — runs ADR-001 consistency check with
--fix via HTTP, so non-MCP agents (Codex) can self-service DB sync without
operator intervention.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/routers/sbom.py

@@ -112,7 +112,7 @@ async def list_snapshots(
     return [SBOMSnapshotRead.model_validate(s) for s in result.scalars().all()]
 
 
-@router.get("/snapshots/{snapshot_id}/", response_model=SBOMSnapshotDetail)
+@router.get("/snapshots/{snapshot_id}", response_model=SBOMSnapshotDetail)
 async def get_snapshot(
     snapshot_id: uuid.UUID,
     session: AsyncSession = Depends(get_session),
@@ -209,7 +209,7 @@ async def licence_report(
     return LicenceReport(groups=licence_groups, copyleft_direct_count=copyleft_direct_count)
 
 
-@router.get("/{repo_slug}/", response_model=SBOMRepoView)
+@router.get("/{repo_slug}", response_model=SBOMRepoView)
 async def get_repo_sbom(
     repo_slug: str,
     session: AsyncSession = Depends(get_session),