address review feedback across the stack

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/state/session/session-data.ts

@@ -1,4 +1,3 @@
-import {getPdsEndpoint, isValidDidDoc} from '@atproto/common-web'
 import {type SessionData} from '@atproto/lex-password-session'
 import {jwtDecode} from 'jwt-decode'
 
@@ -7,6 +6,42 @@ import {isJwtExpired} from '#/lib/jwt'
 import {hasProp} from '#/lib/type-guards'
 import {type SessionAccount} from './types'
 
+/**
+ * The PDS endpoint declared by a DID document, or `undefined`.
+ *
+ * This deliberately mirrors `extractPdsUrl` in `@atproto/lex-password-session`,
+ * the predicate `PasswordSession` uses to route its own requests: the first
+ * service entry whose `id` ends with `#atproto_pds`, taking its
+ * `serviceEndpoint` if it parses as a URL. A stricter predicate here (schema
+ * validation, `type` checks) would let the PERSISTED `pdsUrl` disagree with
+ * the host the live session actually routes to, so the next cold start would
+ * seed the wrong endpoint.
+ */
+function extractPdsUrl(didDoc: SessionData['didDoc']): string | undefined {
+  const services = prop(didDoc, 'service')
+  if (!Array.isArray(services)) {
+    return undefined
+  }
+  const pds = services.find(service => {
+    const id = prop(service, 'id')
+    return typeof id === 'string' && id.endsWith('#atproto_pds')
+  })
+  const endpoint = prop(pds, 'serviceEndpoint')
+  return typeof endpoint === 'string' && URL.canParse(endpoint)
+    ? endpoint
+    : undefined
+}
+
+/**
+ * Read a property off an unknown value the way JS optional chaining would,
+ * without narrowing assumptions about the shape of a `LexMap`.
+ */
+function prop(value: unknown, key: string): unknown {
+  return typeof value === 'object' && value !== null
+    ? (value as Record<string, unknown>)[key]
+    : undefined
+}
+
 /** Whether an access token was issued for a queued (waitlisted) signup. */
 export function isSignupQueued(accessJwt: string | undefined) {
   if (accessJwt) {
@@ -40,11 +75,7 @@ export function sessionDataToSessionAccount(
     return undefined
   }
   const normalizedService = new URL(service).toString()
-  const didDocPdsUrl =
-    session.didDoc && isValidDidDoc(session.didDoc)
-      ? getPdsEndpoint(session.didDoc)
-      : undefined
-  const pdsUrl = didDocPdsUrl ?? storedPdsUrl
+  const pdsUrl = extractPdsUrl(session.didDoc) ?? storedPdsUrl
   return {
     service: normalizedService,
     did: session.did,