[Tracker] Documentation changes

[IzaakGough]

Opening this issue to track issues which are resolved by documentation changes in a single place.

#1019

• Needed doc change: update the EventContext reference to explain Firestore-specific behavior for params, resource, and the auth / authType fields.
• Why: the current EventContext page still says params is for Realtime Database triggers only, and resource examples list Analytics, RTDB, Storage, Auth, and Pub/Sub but not Firestore, even though eventType lists Firestore events. It also still says authType is null for “all except Realtime Database,” which is the same ambiguity raised in the issue.
• Docs checked: EventContext reference

#1502

• Needed doc change: document the caveat that setGlobalOptions() must run before function definitions are evaluated, and that with multi-file JS/ESM layouts, import order / module evaluation can prevent global options from applying as users expect.
• Why: the current 2nd gen reference still states that setGlobalOptions() “sets default options for all functions written using the 2nd gen SDK,” but the docs do not mention the multi-file / ESM import-order caveat or recommend a safe pattern. The organize/manage pages also do not describe this.
• Docs checked: 2nd gen API reference, Manage functions, Organize multiple functions

#1616

• Current docs partially cover this, but there is still a documentation gap:
  • runWith() is still a 1st gen API and remains documented there.
  • 2nd gen functions configure runtime options differently, via trigger options / setGlobalOptions().
  • What is still not stated clearly enough is that legacy builder APIs like runWith(), region(), and auth.user() require importing from firebase-functions/v1 if you are continuing to use 1st gen syntax.
• Changes required:
  • explicitly call out that runWith() is only available on the 1st gen surface,
  • tell users to use firebase-functions/v1 for legacy builder syntax, and
  • point users migrating to 2nd gen to the equivalent options-based configuration pattern.`
• Docs checked: Manage functions (1st gen), 2nd gen upgrade guide

#1877

This PR is resolves #1737. Along with the fix, some documentation changes are needed. In particular, the docs need to make it clear what the timeoutSeconds bounds are for both v1 and v2 functions. Currently these are inconsistent.