fix: PG array format for tags, entity slug prefixes, archive path handling

- knowledge.go: scan tags as []string from pgx (not JSON)
- seed.go: convert tags to PG array format, fix runbook applies_to_type
- convert-wiki.py: fix entity slug prefixes to match inventory.yaml
  (host: not proxmox-host:, ws: not workstation:, service:homelab-mcp with hyphen)
- convert-wiki.py: read from archive/knowledge/ since wiki was archived

internal/knowledge/seed.go

@@ -191,6 +191,9 @@ func ingestRunbook(ctx context.Context, tx pgx.Tx, m map[string]any) error {
 	if riskClass != "" {
 		attrs["risk_class"] = riskClass
 	}
+	if entityType != "" {
+		attrs["applies_to_type"] = entityType
+	}
 	if len(procedure) > 0 {
 		attrs["procedure"] = procedure
 	}
@@ -204,12 +207,6 @@ func ingestRunbook(ctx context.Context, tx pgx.Tx, m map[string]any) error {
 		}
 	}
 
-	if entityType != "" {
-		if err := createEdge(ctx, tx, entitySlug, entityType, "procedure-for", nil); err != nil {
-			return fmt.Errorf("link runbook: %w", err)
-		}
-	}
-
 	return nil
 }
 
@@ -220,7 +217,7 @@ func upsertKnowledgeEntity(ctx context.Context, tx pgx.Tx, slug, entityType, tit
 	}
 
 	hash := contentHash(content)
-	tagsJSON, _ := json.Marshal(tags)
+	tagArray := toPGArray(tags)
 
 	_, err = tx.Exec(ctx,
 		`INSERT INTO knowledge_entities (entity_id, title, content, source, tags, content_hash, created_at, updated_at)
@@ -228,7 +225,7 @@ func upsertKnowledgeEntity(ctx context.Context, tx pgx.Tx, slug, entityType, tit
 		 ON CONFLICT (entity_id) DO UPDATE SET
 		   title = $2, content = $3, source = $4, tags = $5,
 		   content_hash = $6, updated_at = now()`,
-		id, title, content, source, string(tagsJSON), hash)
+		id, title, content, source, tagArray, hash)
 	return err
 }
 
@@ -273,4 +270,19 @@ func createEdge(ctx context.Context, tx pgx.Tx, sourceSlug, targetSlug, relType
 		 DO UPDATE SET attributes = EXCLUDED.attributes`,
 		sourceID, targetID, relType, string(attrsBytes))
 	return err
+}
+
+func toPGArray(tags []string) string {
+	if len(tags) == 0 {
+		return "{}"
+	}
+	out := "{"
+	for i, t := range tags {
+		if i > 0 {
+			out += ","
+		}
+		out += `"` + t + `"`
+	}
+	out += "}"
+	return out
 }