chore: don't redeclare inherited observable Session.name (#34034)

* fix: don't redeclare inherited observable Session.name

`Session extends Instrument` (Log), which declares `name` and converts it to a
MobX observable in its constructor. `Session` redeclared `name: string` only to
narrow the type, but under `useDefineForClassFields: true` that subclass field's
define-semantics initializer runs after `super()` and re-defines the property
MobX already installed — throwing `TypeError: Cannot redefine property: name`
when a Session model is constructed (surfaces in the test-replay viewer's
esbuild bundle, which emits the field; the app's babel build erased it).

Removing the redeclaration (rather than using `declare`, which the app's babel
class-properties pipeline can't strip) fixes it for both build pipelines.
`name` is only assigned in Session, never read, so the inherited type suffices.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* Apply suggestion from @ryanthemanuel

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ryanthemanuel

packages/reporter/src/sessions/sessions-model.ts

@@ -15,7 +15,11 @@ export interface SessionProps extends InstrumentProps {
 }
 
 export default class Session extends Instrument {
-  name: string
+  // `name` is inherited from Instrument (and made observable in its
+  // constructor). Do NOT redeclare it as a class field: under
+  // useDefineForClassFields a subclass field re-defines the inherited
+  // observable and throws "Cannot redefine property: name" when
+  // reporter is embedded into test-replay as a submodule.
   status: string
   isGlobalSession: boolean = false
   tagType: string