fix(rpc): reject a blank GitHub owner or repo

normalizeTaskProviderIdentity treats a blank owner or repo as no identity at
all, but the schema accepted '' and whitespace-only, so the two disagreed about
the same payload. Refined rather than trimmed: trimming would rewrite the
parsed value and change what the handler receives.

Claude-Session: https://claude.ai/code/session_01JNnE9qzUZMMnqpZWCqM3nb

src/main/runtime/rpc/methods/task-provider-identity.test.ts

@@ -108,3 +108,34 @@ describe('task provider identity RPC validation', () => {
     ).toBe(false)
   })
 })
+
+describe('github identity blank fields', () => {
+  // The normalizer treats a blank owner or repo as no identity, so the schema must agree.
+  it.each(['', '   ', '\t'])('rejects a blank owner %j', (owner) => {
+    expect(
+      TaskProviderIdentity.safeParse({ provider: 'github', owner, repo: 'orca' }).success
+    ).toBe(false)
+  })
+
+  it.each(['', '  '])('rejects a blank repo %j', (repo) => {
+    expect(
+      TaskProviderIdentity.safeParse({ provider: 'github', owner: 'stablyai', repo }).success
+    ).toBe(false)
+  })
+
+  it('still accepts a populated identity', () => {
+    expect(
+      TaskProviderIdentity.safeParse({ provider: 'github', owner: 'stablyai', repo: 'orca' })
+        .success
+    ).toBe(true)
+  })
+
+  it('leaves the parsed value untrimmed, so no wire bytes change', () => {
+    const parsed = TaskProviderIdentity.safeParse({
+      provider: 'github',
+      owner: ' stablyai ',
+      repo: 'orca'
+    })
+    expect(parsed.success && parsed.data?.owner).toBe(' stablyai ')
+  })
+})

src/shared/rpc-contract/automation-params.ts

@@ -57,13 +57,21 @@ export const OptionalNullablePlainString = z
   .pipe(z.union([z.string(), z.null(), z.undefined()]))
   .optional()
 
+// A GitHub identity is only usable with both fields present and non-blank.
+const GithubIdentityField = z.string().refine((value) => value.trim().length > 0, {
+  message: 'Required'
+})
+
 export const TaskProviderIdentity = z
   .discriminatedUnion('provider', [
     z
       .object({
         provider: z.literal('github'),
-        owner: z.string(),
-        repo: z.string(),
+        // Why refine, not .trim(): normalizeTaskProviderIdentity treats a blank owner or repo as
+        // no identity at all, so blank must be rejected here — but trimming would rewrite the
+        // parsed value and change what the handler receives.
+        owner: GithubIdentityField,
+        repo: GithubIdentityField,
         host: z.string().optional()
       })
       .passthrough(),