feat(auth): add PAT auth, scoped REST/MCP access, CSRF, and tenant isolation

Introduce Personal Access Tokens (nzp_*) as a stateless auth path alongside
JWT, gated per-endpoint by a scope middleware (nezha:{resource}:{verb}) with
fail-closed empty-scope defaults and a server-id whitelist. Self-management
endpoints (profile, api-tokens, oauth2 bind, refresh-token) explicitly reject
PATs to block privilege-escalation chains. A revoke registry tears down active
long-lived connections (terminal, fm, ws, transfer, mcp) the moment a PAT is
deleted, with a tombstone closing the revoke->register race.

Add an MCP endpoint that proxies tool calls (exec, fs read/write/delete,
transfer) to agents over gRPC, guarded by origin/DNS-rebinding checks, a
per-token rate limiter, audit logging, and a kill switch. Serialize all
sends through the IOStream wrapper to honour grpc-go's concurrency contract.

Add CSRF double-submit protection on unsafe cookie-authenticated methods,
exempting authenticated PAT requests by context identity (not a forgeable
Authorization header). Apply visibility/whitelist filtering consistently
across list, get-by-id, and mutate paths to enforce tenant isolation.

Migrate legacy mcp:* scopes: rewrite read/exec to nezha:* equivalents and
drop dangerous write/delete/wildcard grants.

Co-authored-by: cloudcode <cloudcode@users.noreply.github.com>

cmd/dashboard/controller/mcp_ratelimit_malformed_test.go

@@ -0,0 +1,74 @@
+package controller
+
+import (
+	"bytes"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/nezhahq/nezha/model"
+	"github.com/nezhahq/nezha/service/singleton"
+)
+
+func mcpEndpointRawCtx(t *testing.T, tok *model.APIToken, raw []byte) (*gin.Context, *httptest.ResponseRecorder) {
+	t.Helper()
+	gin.SetMode(gin.TestMode)
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+	c.Request = httptest.NewRequest("POST", "/mcp", bytes.NewReader(raw))
+	c.Request.Header.Set("Content-Type", "application/json")
+	c.Set(apiTokenCtxKey, tok)
+	c.Set(model.CtxKeyAPIToken, tok)
+	return c, w
+}
+
+func mcpRateLimitTestSetup(t *testing.T, budget int) *model.APIToken {
+	t.Helper()
+	originalConf := singleton.Conf
+	originalLimiter := mcpRateLimiterShared
+	t.Cleanup(func() {
+		singleton.Conf = originalConf
+		mcpRateLimiterShared = originalLimiter
+	})
+	cfg := &model.Config{}
+	cfg.SetMCPEnabled(true)
+	singleton.Conf = &singleton.ConfigClass{Config: cfg}
+	mcpRateLimiterShared = newMCPRateLimiter(budget, budget)
+	return &model.APIToken{ID: 4243, UserID: 1}
+}
+
+// A flood of tools/call requests whose params fail to parse must still consume
+// the per-token budget. Otherwise a valid PAT bypasses the limiter by always
+// sending malformed arguments.
+func TestMCPMalformedToolsCallParamsCountsAgainstRateLimit(t *testing.T) {
+	tok := mcpRateLimitTestSetup(t, 2)
+
+	raw := []byte(`{"jsonrpc":"2.0","id":1,"method":"tools/call","params":"not-an-object"}`)
+
+	for i := 0; i < 5; i++ {
+		c, _ := mcpEndpointRawCtx(t, tok, raw)
+		mcpEndpoint(c)
+	}
+
+	if mcpRateLimiterShared.Allow(tok.ID) {
+		t.Fatal("malformed tools/call params must still consume the rate budget; limiter not saturated")
+	}
+}
+
+// A flood of unparseable JSON-RPC envelopes from an authenticated PAT must also
+// consume the budget.
+func TestMCPMalformedEnvelopeCountsAgainstRateLimit(t *testing.T) {
+	tok := mcpRateLimitTestSetup(t, 2)
+
+	raw := []byte(`{not valid json`)
+
+	for i := 0; i < 5; i++ {
+		c, _ := mcpEndpointRawCtx(t, tok, raw)
+		mcpEndpoint(c)
+	}
+
+	if mcpRateLimiterShared.Allow(tok.ID) {
+		t.Fatal("malformed JSON-RPC envelope must still consume the rate budget; limiter not saturated")
+	}
+}