feat: add mind model with versioned personality, templates and self-model

Phase 2. Minds are rows with a slug, status (active/disabled/archived),
cognitive configuration and a pointer to the current personality version.
Personalities are structured (identity, values, traits, communication,
behaviour, free text) with a deterministic Brief() used by prompts and the
editor preview. Every change appends a personality_versions row protected
by the append-only trigger; restore copies an old version forward.
Templates carry reusable personalities; minds record their overrides so a
template can be re-applied without losing mind-specific edits. The
self-model starts with structural limitations the mind cannot drop
(no policy changes, no influence over shutdown, no cross-mind access).

API, UI (list, overview, editor with sliders/diff/history/import/export,
template editor) and noemactl mind/template commands. All mutations are
audited with field-level diffs.

internal/api/api_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/andydixon/noema/internal/audit"
 	"github.com/andydixon/noema/internal/auth"
 	"github.com/andydixon/noema/internal/config"
+	"github.com/andydixon/noema/internal/minds"
 	"github.com/andydixon/noema/internal/observability"
 	"github.com/andydixon/noema/internal/storage"
 	"github.com/andydixon/noema/migrations"
@@ -26,7 +27,7 @@ func testServer(t *testing.T) (*httptest.Server, string) {
 	cfg.DatabaseURL = "postgres://test"
 	log := slog.New(slog.DiscardHandler)
 	deps := app.Deps{Config: cfg, Log: log, DB: pool, Auth: auth.NewService(pool, time.Hour, 2*time.Hour),
-		Audit: audit.New(pool, log), Metrics: observability.NewMetrics(), Migrations: migrations.FS, Started: time.Now()}
+		Audit: audit.New(pool, log), Metrics: observability.NewMetrics(), Minds: minds.NewStore(pool), Migrations: migrations.FS, Started: time.Now()}
 	ctx := context.Background()
 	u, err := deps.Auth.CreateUser(ctx, "admin", "administrator-pass", auth.RoleAdministrator)
 	if err != nil {