feat(repository): refactor query/mutation ports with capability-safe

interfaces

- refactor: split UserRepository into AuthUserRepository and
  AdminUserRepository capabilities
- refactor: split SessionRepository into AuthSessionRepository and
  repository-owned CLI/admin methods
- refactor: replace generic Repository Update/Delete with
  operation-specific params and ownership predicates
- refactor: replace CredentialRepository generic CRUD with
  passkey-specific methods
- refactor: replace FileRepository generic Create/Update/Delete with
  UploadedFileParams, DirectoryParams, and owned soft-delete
- refactor: remove repository fields from WebApp struct; repositories
  are now composition-time wiring only
- feat: add domain error kinds ErrParentNotFound, ErrParentNotDir,
  ErrDirectoryNotEmpty, ErrInvalidMove
- feat: add CredentialTypeAppPasskey constant
- feat: add testutil.SetUserAdmin for test fixture setup that bypasses
  production service ports
- test: add architecture test banning GORM Save in repository package
- test: add capability interface contract tests ensuring each service
  receives the minimal interface
- test: add blockingStorage helper for concurrent promotion tests
- test: add preserved DSN parameter test for sqliteImmediateDSN
- docs: update architecture decisions with repository write rules and
  capability separation
- docs: update roadmap to clarify atomic single-use refresh sessions
- docs: add -race test target to development docs

internal/repository/db_test.go

@@ -1,11 +1,31 @@
 package repository
 
 import (
+	"net/url"
+	"strings"
 	"testing"
 
 	"github.com/dhao2001/mygo/internal/config"
 )
 
+func TestSQLiteImmediateDSNPreservesParameters(t *testing.T) {
+	dsn := sqliteImmediateDSN("file:test.db?cache=shared&_busy_timeout=9000&_txlock=deferred")
+	base, rawQuery, found := strings.Cut(dsn, "?")
+	if !found || base != "file:test.db" {
+		t.Fatalf("DSN base = %q, want file:test.db", base)
+	}
+	query, err := url.ParseQuery(rawQuery)
+	if err != nil {
+		t.Fatalf("parse DSN query: %v", err)
+	}
+	if query.Get("cache") != "shared" || query.Get("_busy_timeout") != "9000" {
+		t.Fatalf("DSN did not preserve parameters: %q", dsn)
+	}
+	if query.Get("_txlock") != "immediate" {
+		t.Fatalf("_txlock = %q, want immediate", query.Get("_txlock"))
+	}
+}
+
 func TestOpenSQLite(t *testing.T) {
 	cfg := config.DatabaseConfig{
 		Driver: "sqlite3",