feat(api): local-password authentication backend

Add username+password login for Owner/Operator staff accounts on
op.console, the primary web login when Zero Trust is not in front of the
API. Three handlers form the whole surface: login mints a server-side
session cookie, logout revokes it idempotently, and change-password
re-verifies the current password before rotating the hash and clearing
must_change_password.

- Session cookies are HttpOnly+Secure+SameSite=Lax, host-only, stored
  server-side as a SHA-256 hash with a 12h TTL.
- Login is anti-enumeration: every failure runs a uniform bcrypt compare
  against a dummy hash and returns the same vague error.
- Credential-bearing writes require Content-Type: application/json,
  returning 415 otherwise, to close the cross-site form-POST forgery
  vector as a belt to the SameSite cookie.
- Local auth fails closed: login is rejected unless local_auth_enabled
  is set, so a Zero-Trust-only deployment never accepts a local password.
- Extend the users table with a nullable password_hash and
  must_change_password; staff are role=admin rows with a hash, players
  are role=user rows with hash NULL.
- /me now reports must_change_password so the panel can force a
  first-login change.

Covered by Go unit tests (handlers, content-type guard, anti-enumeration,
forced-change lockdown) and the OpenAPI route-parity gate.

go.mod

@@ -4,7 +4,12 @@ go 1.26
 
 require (
 	github.com/BurntSushi/toml v1.4.0
+	github.com/charmbracelet/bubbles v1.0.0
+	github.com/charmbracelet/bubbletea v1.3.10
+	github.com/charmbracelet/lipgloss v1.1.0
+	github.com/golang-jwt/jwt/v5 v5.2.1
 	github.com/jackc/pgx/v5 v5.7.1
+	golang.org/x/crypto v0.27.0
 	k8s.io/api v0.31.3
 	k8s.io/apimachinery v0.31.3
 	k8s.io/client-go v0.31.0
@@ -13,10 +18,20 @@ require (
 )
 
 require (
+	github.com/atotto/clipboard v0.1.4 // indirect
+	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/charmbracelet/colorprofile v0.4.1 // indirect
+	github.com/charmbracelet/x/ansi v0.11.6 // indirect
+	github.com/charmbracelet/x/cellbuf v0.0.15 // indirect
+	github.com/charmbracelet/x/term v0.2.2 // indirect
+	github.com/clipperhouse/displaywidth v0.9.0 // indirect
+	github.com/clipperhouse/stringish v0.1.1 // indirect
+	github.com/clipperhouse/uax29/v2 v2.5.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/emicklei/go-restful/v3 v3.11.0 // indirect
+	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
 	github.com/evanphx/json-patch/v5 v5.9.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.7.0 // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
@@ -24,7 +39,6 @@ require (
 	github.com/go-openapi/jsonreference v0.20.2 // indirect
 	github.com/go-openapi/swag v0.22.4 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
-	github.com/golang-jwt/jwt/v5 v5.2.1 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/google/gnostic-models v0.6.8 // indirect
@@ -37,23 +51,31 @@ require (
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/lucasb-eyer/go-colorful v1.3.0 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/mattn/go-localereader v0.0.1 // indirect
+	github.com/mattn/go-runewidth v0.0.19 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 // indirect
+	github.com/muesli/cancelreader v0.2.2 // indirect
+	github.com/muesli/termenv v0.16.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/prometheus/client_golang v1.19.1 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.55.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
-	golang.org/x/crypto v0.27.0 // indirect
-	golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc // indirect
+	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
+	golang.org/x/exp v0.0.0-20231006140011-7918f672742d // indirect
 	golang.org/x/net v0.26.0 // indirect
 	golang.org/x/oauth2 v0.21.0 // indirect
 	golang.org/x/sync v0.8.0 // indirect
-	golang.org/x/sys v0.25.0 // indirect
+	golang.org/x/sys v0.38.0 // indirect
 	golang.org/x/term v0.24.0 // indirect
 	golang.org/x/text v0.18.0 // indirect
 	golang.org/x/time v0.3.0 // indirect