[WIP] Onboarding: extend bespoke welcome to all MANAGE_TEAM sizes

[marcochavezf]

Explanation of Change

🚧 WIP / HOLD — do not merge yet.

• Welcome copy is placeholder pending the team's review (lighter ~50w vs. middle ~70w variants, per-tier vs. uniform value-teaser language).
• Web-Expensify counterpart #52519 (server-side guide-block append) needs to be in production before this can flip the gate safely.
• A small companion edit to Web-Expensify UserAPI::queueAdminsRoomWelcome (extend isMicroManageTeamCohort to all MANAGE_TEAM sizes) will land alongside this PR.

This PR opens the deterministic bespoke welcome path to every MANAGE_TEAM cohort. Today it's gated to MICRO sizes (1-10) only; SMALL/MEDIUM_SMALL/MEDIUM/LARGE (11+) still see the legacy task-list welcome. After this lands and the Web-E side ships:

1. Every MANAGE_TEAM signup gets the optimistic Concierge welcome body + pregenerated followup chips.
2. For TEAM 11+ specifically, the server-side append in queueAdminsRoomWelcome (Web-E PR We created multiple workspaces for user in onboarding #52519) inserts a "you also have {guide name} assigned to your account as your dedicated onboarding specialist" paragraph with a Book a call with {name} link between the welcome body and the chips — so the human onboarding specialist gets introduced distinctly from Concierge instead of conflated into one greeting.

Two changes in this PR:

1. isPhase1Cohort extended to cover SMALL, MEDIUM_SMALL, MEDIUM, LARGE alongside the existing MICRO_SMALL / MICRO_MEDIUM / MICRO. (src/libs/ReportUtils.ts:11708)
2. Welcome speaker swap — drops the "I'm your Expensify setup specialist" framing in getBespokeWelcomeMessage per Daniel's onboarding-test feedback (2026-04-30 video at ~6:33). Concierge is now the speaker; the assigned human guide gets introduced server-side. Tier-specific value teasers reworded to point at the followup chips. (src/libs/ReportUtils.ts:11641)

Fixed Issues

$ https://github.com/Expensify/Expensify/issues/621176

Tests

1. Sign up a fresh Gmail account on dev.new.expensify.com:8082 (incognito).
2. Pick Manage my team's expenses then 11-25 employees (any TEAM 11+ size). Pick any accounting integration. Continue.
3. Open the new #admins chat. Wait until Concierge posts the welcome message with three followup chips.
4. Confirm the welcome message:
   • Starts with "I'm Concierge — I'll help you get Expensify working for your team" (NOT "I'm your Expensify setup specialist").
   • For TEAM 11+, includes a separate paragraph introducing your assigned guide by name with a clickable Book a call link (this comes from the server-side append; depends on Web-Expensify We created multiple workspaces for user in onboarding #52519 being deployed).
   • Has three followup chips at the bottom.
5. Click any followup chip — the canned answer renders inline.
6. Repeat for 1-4 employees (MICRO segment) — confirm welcome still works as it does on production today, with the speaker now reading "I'm Concierge" instead of "setup specialist".

• Verify that no errors appear in the JS console.

Offline tests

No behavior change while offline — completeOnboarding queues the request the same way it already did. While offline the welcome message + chips render optimistically as before; the server-rendered guide block (if applicable) materializes via reportActionID reconciliation when the request flushes on reconnect.

QA Steps

Same as Tests above on staging once both sides ship:

1. staging.new.expensify.com fresh signup.
2. Repeat with 26-100, 101-1000, 1001+ employees — confirm bespoke welcome lands in each, and the guide-introduction paragraph + book-a-call link appears for each.
3. Confirm an MICRO (1-10) signup still works as today (no guide-block paragraph; Concierge is both voice and onboarding contact).

• Verify that no errors appear in the JS console.

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
• I included screenshots or videos for tests on all platforms (pending — will add once copy is finalized to avoid re-recording)
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• I verified there are no console errors
• I followed proper code patterns
• I verified all code is DRY
• I verified the language code change works through localization