Add local login, agent extra log paths, IPv4/IPv6 metrics; remediate security audit findings

This is a large squashed commit covering two batches of prior uncommitted
work plus a full security-audit remediation pass, kept together because
go.mod/go.sum and several shared files (main.go, handler.go) were touched
by both and splitting risked non-building intermediate commits.

Features (built earlier, previously uncommitted):
- Local username/password login for single-tenant deployments with no
  SSO configured (api/localauth, alerting/internal/sessioncheck,
  sentryctl users, web/src/routes/login, metadata migrations 0040/0041).
- Remotely-editable additional log file paths for agents, on top of
  their existing primary source (api/agents, agent/sentry-agent
  extra-file-path diffing, web agent config UI).
- IPv4/IPv6 addresses reported alongside other host system metrics.

Security audit remediation (this pass, all live-verified in production):
- Critical: block ClickHouse SSRF table functions (url/remote/file/s3/...)
  in the raw-SQL query escape hatch.
- High: deny sensitive paths and require Admin to add agent
  extra_file_paths (Editor could previously point an agent at /etc/shadow
  or an SSH key); alerting webhook targets now validate against
  internal/metadata/loopback addresses, both at creation and send time;
  alerting's session middleware now enforces an Editor+ floor on
  mutating requests instead of "any authenticated session"; bumped
  goxmldsig to close a SAML signature-verification bypass (GO-2026-4753).
- Medium: per-IP login rate limiting; security response headers
  (HSTS/CSP/nosniff/X-Frame-Options/Referrer-Policy/Permissions-Policy)
  on web/nginx.conf; a DevCredentialWarnings check in every Go service's
  config loader, logging loudly at startup if a deployment is still on
  docker-compose.yml's literal dev-only credentials; dependency bumps
  (golang.org/x/text, grpc, x/net, quick-xml, h2) across every affected
  Go module and both Rust crates, including a previously-uncovered x/net
  vulnerability in deploy/operator; a new security-scan.yml CI workflow
  running cargo-deny/govulncheck/npm-audit, mirroring the existing
  license-compliance.yml matrix shape.
- Low: removed sentryctl's plaintext --password flag (shell
  history/`ps` exposure) in favor of stdin and a --password-stdin flag
  for reset-password's optional specific-password path; a dummy bcrypt
  comparison closes a login response-time username-enumeration
  side-channel.

api/localauth/fake_test.go

@@ -0,0 +1,127 @@
+package localauth
+
+import (
+	"context"
+	"strconv"
+	"time"
+
+	"github.com/sentry/sentry/api/authz"
+)
+
+// fakeStore implements both store (handler.go) and sessionStore
+// (authorizer.go) -- a real *Store satisfies both too, this is just the
+// in-memory test double, same "fake enforces the same invariants the
+// real pgx-backed Store does" posture dashboards/handler_test.go's
+// fakeStore documents.
+type fakeStore struct {
+	users      map[string]*User // by id
+	hashes     map[string]string
+	byUsername map[string]string // username -> id
+	sessions   map[string]Session
+	nextID     int
+	createErr  error
+}
+
+func newFakeStore() *fakeStore {
+	return &fakeStore{
+		users:      map[string]*User{},
+		hashes:     map[string]string{},
+		byUsername: map[string]string{},
+		sessions:   map[string]Session{},
+	}
+}
+
+func (f *fakeStore) CreateUser(_ context.Context, username, passwordHash string, role authz.Role) (*User, error) {
+	if f.createErr != nil {
+		return nil, f.createErr
+	}
+	if _, ok := f.byUsername[username]; ok {
+		return nil, ErrUsernameTaken
+	}
+	f.nextID++
+	id := "user-" + strconv.Itoa(f.nextID)
+	u := &User{ID: id, Username: username, Role: role, CreatedAt: time.Now()}
+	f.users[id] = u
+	f.hashes[id] = passwordHash
+	f.byUsername[username] = id
+	return u, nil
+}
+
+func (f *fakeStore) ListUsers(_ context.Context) ([]User, error) {
+	var out []User
+	for _, u := range f.users {
+		out = append(out, *u)
+	}
+	return out, nil
+}
+
+func (f *fakeStore) GetUserForLogin(_ context.Context, username string) (*User, string, error) {
+	id, ok := f.byUsername[username]
+	if !ok {
+		return nil, "", ErrNotFound
+	}
+	return f.users[id], f.hashes[id], nil
+}
+
+func (f *fakeStore) GetUserByID(_ context.Context, id string) (*User, error) {
+	u, ok := f.users[id]
+	if !ok {
+		return nil, ErrNotFound
+	}
+	return u, nil
+}
+
+func (f *fakeStore) DeleteUser(_ context.Context, id string) error {
+	u, ok := f.users[id]
+	if !ok {
+		return ErrNotFound
+	}
+	delete(f.users, id)
+	delete(f.hashes, id)
+	delete(f.byUsername, u.Username)
+	for hash, sess := range f.sessions {
+		if sess.UserID == id {
+			delete(f.sessions, hash)
+		}
+	}
+	return nil
+}
+
+func (f *fakeStore) SetPasswordHash(_ context.Context, userID, hash string) error {
+	if _, ok := f.users[userID]; !ok {
+		return ErrNotFound
+	}
+	f.hashes[userID] = hash
+	for h, sess := range f.sessions {
+		if sess.UserID == userID {
+			delete(f.sessions, h)
+		}
+	}
+	return nil
+}
+
+func (f *fakeStore) CountLocalUsers(_ context.Context) (int, error) {
+	return len(f.users), nil
+}
+
+func (f *fakeStore) CreateSession(_ context.Context, userID, tenantID string, role authz.Role, ttl time.Duration) (string, error) {
+	raw, hash, err := newOpaqueToken()
+	if err != nil {
+		return "", err
+	}
+	f.sessions[hash] = Session{UserID: userID, TenantID: tenantID, Role: role, ExpiresAt: time.Now().Add(ttl)}
+	return raw, nil
+}
+
+func (f *fakeStore) GetSession(_ context.Context, tokenHash string) (*Session, error) {
+	sess, ok := f.sessions[tokenHash]
+	if !ok || sess.ExpiresAt.Before(time.Now()) {
+		return nil, ErrNotFound
+	}
+	return &sess, nil
+}
+
+func (f *fakeStore) DeleteSessionByHash(_ context.Context, tokenHash string) error {
+	delete(f.sessions, tokenHash)
+	return nil
+}