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/httpapi/knowledge.go

@@ -2,10 +2,8 @@ package httpapi
 
 import (
 	"context"
-	"encoding/json"
 
 	"github.com/dtoro/oikos/internal/httpapi/gen"
-	"github.com/google/uuid"
 )
 
 func (s *Server) SearchKnowledge(ctx context.Context, request gen.SearchKnowledgeRequestObject) (gen.SearchKnowledgeResponseObject, error) {
@@ -33,17 +31,15 @@ func (s *Server) SearchKnowledge(ctx context.Context, request gen.SearchKnowledg
 	items := []gen.KnowledgeHit{}
 
 	for rows.Next() {
-		var slug, eType, title, source, tagJSON string
+		var slug, eType, title, source string
+		var tags []string
 		var rank float32
 		var snippet *string
 
-		if err := rows.Scan(&slug, &eType, &title, &source, &tagJSON, &rank, &snippet); err != nil {
+		if err := rows.Scan(&slug, &eType, &title, &source, &tags, &rank, &snippet); err != nil {
 			return nil, err
 		}
 
-		var tags []string
-		json.Unmarshal([]byte(tagJSON), &tags)
-
 		hitType := gen.Document
 		switch eType {
 		case "investigation":
@@ -52,9 +48,6 @@ func (s *Server) SearchKnowledge(ctx context.Context, request gen.SearchKnowledg
 			hitType = gen.Runbook
 		}
 
-		id, _ := uuid.Parse("")
-		_ = id // not needed for response since we use slug
-
 		items = append(items, gen.KnowledgeHit{
 			Slug:       slug,
 			Title:      title,
@@ -107,13 +100,12 @@ func (s *Server) GetEntityKnowledge(ctx context.Context, request gen.GetEntityKn
 
 	items := []gen.KnowledgeHit{}
 	for rows.Next() {
-		var slug, eType, title, source, tagJSON string
+		var slug, eType, title, source string
 		var tags []string
 
-		if err := rows.Scan(&slug, &eType, &title, &source, &tagJSON); err != nil {
+		if err := rows.Scan(&slug, &eType, &title, &source, &tags); err != nil {
 			return nil, err
 		}
-		json.Unmarshal([]byte(tagJSON), &tags)
 
 		hitType := gen.Document
 		switch eType {