feat: PlanetScale managed-MySQL preset with setup guide and host detection (Task 3)

desktop/src/components/connections/DetailedConnectionForm.tsx

@@ -8,7 +8,7 @@ import type { ConnectionFormData } from "./connectionFormData";
 export interface DetailedConnectionFormProps {
   form: ConnectionFormData;
   onChange: (updates: Partial<ConnectionFormData>) => void;
-  managedPreset?: "supabase" | "neon" | null;
+  managedPreset?: "supabase" | "neon" | "planetscale" | null;
 }
 
 export function DetailedConnectionForm({ form, onChange, managedPreset }: DetailedConnectionFormProps) {

desktop/src/components/connections/GeneralTab.tsx

@@ -7,7 +7,7 @@ import type { ConnectionFormData } from "./connectionFormData";
 export interface GeneralTabProps {
   form: ConnectionFormData;
   onChange: (updates: Partial<ConnectionFormData>) => void;
-  managedPreset?: "supabase" | "neon" | null;
+  managedPreset?: "supabase" | "neon" | "planetscale" | null;
 }
 
 const AUTH_OPTIONS = ["User & Password"];
@@ -32,7 +32,7 @@ export function GeneralTab({ form, onChange, managedPreset }: GeneralTabProps) {
         )}
         {managedPreset && (
           <p className="text-xs text-accent-muted mt-1.5">
-            {managedPreset === "supabase" ? "Supabase" : "NeonDB"} requires SSL — enable it under SSH / SSL.
+            {managedPreset === "supabase" ? "Supabase" : managedPreset === "planetscale" ? "PlanetScale" : "NeonDB"} requires SSL — enable it under SSH / SSL.
           </p>
         )}
       </div>

desktop/src/components/connections/NewConnectionScreen.tsx

@@ -74,7 +74,7 @@ export function NewConnectionScreen({
 }: NewConnectionScreenProps) {
     const [stage, setStage] = useState<Stage>("entry");
     const [managedPreset, setManagedPreset] = useState<
-        "supabase" | "neon" | null
+        "supabase" | "neon" | "planetscale" | null
     >(null);
     const [form, setForm] = useState<ConnectionFormData>(() =>
         createEmptyForm(
@@ -99,7 +99,7 @@ export function NewConnectionScreen({
         const parsed = parseConnectionString(value);
         if (parsed) {
             const provider =
-                parsed.db_type === "postgresql"
+                parsed.db_type === "postgresql" || parsed.db_type === "mysql"
                     ? detectProviderFromHost(parsed.host)
                     : null;
             setManagedPreset(provider);
@@ -139,7 +139,9 @@ export function NewConnectionScreen({
         (id: ProviderId) => {
             const provider = getProviderById(id)!;
             setManagedPreset(
-                provider.isManagedPreset ? (id as "supabase" | "neon") : null,
+                provider.isManagedPreset
+                    ? (id as "supabase" | "neon" | "planetscale")
+                    : null,
             );
             revealConfigured({
                 db_type: provider.dbType,
@@ -148,6 +150,7 @@ export function NewConnectionScreen({
                         ? null
                         : getDefaultPort(provider.dbType),
                 ...(provider.dbType === "sqlite" ? { host: "" } : {}),
+                ...(id === "planetscale" ? { ssl_mode: "verify-full" } : {}),
             });
         },
         [revealConfigured],
@@ -164,7 +167,7 @@ export function NewConnectionScreen({
                     const parsed = parseConnectionString(value);
                     if (parsed) {
                         const provider =
-                            parsed.db_type === "postgresql"
+                            parsed.db_type === "postgresql" || parsed.db_type === "mysql"
                                 ? detectProviderFromHost(parsed.host)
                                 : null;
                         setManagedPreset(provider);

desktop/src/components/connections/ProviderSetupGuide.tsx

@@ -3,12 +3,13 @@ import { ChevronDown } from "lucide-react";
 import { SETUP_GUIDES } from "../../lib/providers";
 
 interface ProviderSetupGuideProps {
-  provider: "supabase" | "neon";
+  provider: "supabase" | "neon" | "planetscale";
 }
 
-const SSL_NOTE: Record<"supabase" | "neon", string> = {
+const SSL_NOTE: Record<"supabase" | "neon" | "planetscale", string> = {
   supabase: "SSL is required by Supabase.",
   neon: "Neon requires SSL.",
+  planetscale: "PlanetScale requires SSL with identity verification.",
 };
 
 export function ProviderSetupGuide({ provider }: ProviderSetupGuideProps) {

desktop/src/components/connections/ProviderTabsGrid.tsx

@@ -24,7 +24,7 @@ export function ProviderTabsGrid({ selectedId, onSelect }: ProviderTabsGridProps
             }`}
           >
             <span className="w-8 h-8 flex items-center justify-center">
-              {p.isManagedPreset ? <ProviderIcon id={p.id as "supabase" | "neon"} size={24} /> : <DbIcon type={p.dbType} size={24} />}
+              {p.isManagedPreset ? <ProviderIcon id={p.id as "supabase" | "neon" | "planetscale"} size={24} /> : <DbIcon type={p.dbType} size={24} />}
             </span>
             <span className="text-sm font-medium">{p.label}</span>
             {p.isManagedPreset && (

desktop/src/lib/connectionString.test.ts

@@ -194,6 +194,19 @@ describe("detectProviderFromHost", () => {
     });
   });
 
+describe("detectProviderFromHost", () => {
+  it("detects PlanetScale access hosts", () => {
+    expect(detectProviderFromHost("xxxx.us-east-2.psdb.cloud")).toBe("planetscale");
+    expect(detectProviderFromHost("aws.connect.psdb.cloud")).toBe("planetscale");
+  });
+
+  it("still detects supabase and neon", () => {
+    expect(detectProviderFromHost("db.abc.supabase.co")).toBe("supabase");
+    expect(detectProviderFromHost("ep-1-pooler.eu.aws.neon.tech")).toBe("neon");
+    expect(detectProviderFromHost("example.com")).toBeNull();
+  });
+});
+
 describe("buildConnectionUrl", () => {
   it("builds a PostgreSQL URL with password and sslmode", () => {
     const url = buildConnectionUrl(

desktop/src/lib/connectionString.ts

@@ -85,10 +85,13 @@ export function looksLikeConnectionString(input: string): boolean {
 /** Detect a managed-PostgreSQL provider from a connection host, purely for
  *  UI highlighting. Returns `"supabase"` / `"neon"` / `null`. db_type is
  *  unaffected (both presets persist as `postgresql`). */
-export function detectProviderFromHost(host: string): "supabase" | "neon" | null {
+export function detectProviderFromHost(
+  host: string,
+): "supabase" | "neon" | "planetscale" | null {
   const h = host.toLowerCase();
   if (h.endsWith(".supabase.co")) return "supabase";
   if (h.endsWith(".neon.tech")) return "neon";
+  if (h.endsWith(".psdb.cloud")) return "planetscale";
   return null;
 }
 

desktop/src/lib/dbIcons.tsx

@@ -1,4 +1,4 @@
-import { siPostgresql, siMysql, siMariadb, siSqlite, siRedis, siSupabase, siNeon } from "simple-icons";
+import { siPostgresql, siMysql, siMariadb, siSqlite, siRedis, siSupabase, siNeon, siPlanetscale } from "simple-icons";
 import type { DbType } from "./types";
 
 // Brand colors from simple-icons
@@ -64,16 +64,18 @@ export const DB_ICONS: Record<DbType, string> = {
 
 // ── Managed-PostgreSQL provider icons (Supabase, NeonDB) ──────────
 // These are NOT DbType values; connections persist as db_type="postgresql".
-type ProviderIconId = "supabase" | "neon";
+type ProviderIconId = "supabase" | "neon" | "planetscale";
 
 const PROVIDER_ICON_DATA: Record<ProviderIconId, { hex: string; path: string }> = {
   supabase: { hex: `#${siSupabase.hex}`, path: siSupabase.path },
   neon: { hex: `#${siNeon.hex}`, path: siNeon.path },
+  planetscale: { hex: `#${siPlanetscale.hex}`, path: siPlanetscale.path },
 };
 
 export const PROVIDER_LABELS: Record<ProviderIconId, string> = {
   supabase: "Supabase",
   neon: "NeonDB",
+  planetscale: "PlanetScale",
 };
 
 interface ProviderIconProps {

desktop/src/lib/providers.test.ts

@@ -2,9 +2,9 @@ import { describe, it, expect } from "vitest";
 import { PROVIDER_TABS, getProviderById, SETUP_GUIDES } from "./providers";
 
 describe("providers", () => {
-  it("defines exactly 7 provider tabs in order", () => {
+  it("defines exactly 8 provider tabs in order", () => {
     expect(PROVIDER_TABS.map((p) => p.id)).toEqual([
-      "postgresql", "mysql", "mariadb", "sqlite", "redis", "supabase", "neon",
+      "postgresql", "mysql", "mariadb", "sqlite", "redis", "supabase", "neon", "planetscale",
     ]);
   });
 
@@ -40,4 +40,20 @@ describe("providers", () => {
     expect(SETUP_GUIDES.supabase.sslRequired).toBe(true);
     expect(SETUP_GUIDES.neon.sslRequired).toBe(true);
   });
+});
+
+describe("PlanetScale preset", () => {
+  it("registers as a managed MySQL preset persisting db_type mysql", () => {
+    const tab = PROVIDER_TABS.find((p) => p.id === "planetscale");
+    expect(tab).toBeDefined();
+    expect(tab!.dbType).toBe("mysql");
+    expect(tab!.isManagedPreset).toBe(true);
+  });
+
+  it("ships a setup guide requiring SSL with concrete steps", () => {
+    const guide = SETUP_GUIDES.planetscale;
+    expect(guide.sslRequired).toBe(true);
+    expect(guide.steps.length).toBeGreaterThanOrEqual(4);
+    expect(guide.steps.some((s) => s.detail.includes("psdb.cloud"))).toBe(true);
+  });
 });

desktop/src/lib/providers.ts

@@ -1,6 +1,6 @@
 import type { DbType } from "./types";
 
-export type ProviderId = "postgresql" | "mysql" | "mariadb" | "sqlite" | "redis" | "supabase" | "neon";
+export type ProviderId = "postgresql" | "mysql" | "mariadb" | "sqlite" | "redis" | "supabase" | "neon" | "planetscale";
 
 export interface ProviderTab {
   id: ProviderId;
@@ -20,6 +20,7 @@ export const PROVIDER_TABS: ProviderTab[] = [
   { id: "redis", label: "Redis", dbType: "redis", isManagedPreset: false },
   { id: "supabase", label: "Supabase", dbType: "postgresql", isManagedPreset: true },
   { id: "neon", label: "NeonDB", dbType: "postgresql", isManagedPreset: true },
+  { id: "planetscale", label: "PlanetScale", dbType: "mysql", isManagedPreset: true },
 ];
 
 export function getProviderById(id: string): ProviderTab | undefined {
@@ -40,7 +41,7 @@ export interface SetupGuide {
 
 /** Static, researched setup instructions. No network calls at runtime.
  *  Content reviewed against the official docs (fetched 2026-08-04, see spec §9). */
-export const SETUP_GUIDES: Record<"supabase" | "neon", SetupGuide> = {
+export const SETUP_GUIDES: Record<"supabase" | "neon" | "planetscale", SetupGuide> = {
   supabase: {
     blurb: "Managed PostgreSQL with a pooled connection string.",
     sslRequired: true,
@@ -66,6 +67,17 @@ export const SETUP_GUIDES: Record<"supabase" | "neon", SetupGuide> = {
       },
     ],
   },
+  planetscale: {
+    blurb: "Managed MySQL (Vitess) with database branching.",
+    sslRequired: true,
+    steps: [
+      { title: "Create a branch password", detail: "In the PlanetScale dashboard open your database → Connect → pick a branch → Create password. The password (pscale_pw_…) is shown ONCE and works only for that branch." },
+      { title: "Copy the credentials", detail: "Note the Access Host URL (e.g. aws.connect.psdb.cloud or xxxx.us-east-2.psdb.cloud), the username, the password, and your database name." },
+      { title: "Fill Host / Port / Database", detail: "Host is the access host, port is 3306, Database is your database name. Save stores the password in your OS keychain." },
+      { title: "SSL is mandatory", detail: "Gridline pre-selects Verify Full — PlanetScale requires TLS with identity verification." },
+      { title: "Vitess caveats", detail: "Passwords are branch-scoped; deleting one disconnects its clients within 5 minutes. With Safe Migrations ON, schema changes go through deploy requests, so the changes queue may be blocked on production branches. Foreign keys follow your database's foreign_key_constraint setting." },
+    ],
+  },
   neon: {
     blurb: "Serverless Postgres with pooled or direct endpoints.",
     sslRequired: true,