docs(product): define zero-setup onboarding journey

[avabbbb]

Purpose

This PR does not add another Agent/runtime feature.

It first defines the product target for OfferU's next phase:

turn the existing Career OS capabilities into a zero-setup consumer journey for non-technical job seekers.

The intended first-run path is:

Install
→ Find my local AI
→ Build Profile from Resume + explicitly authorized AI memory
→ Save first Job from browser
→ Connect job-search inbox
→ Reach a useful Today

Why now

The repository already has strong primitives:

• Tauri + local Python runtime
• local Agent discovery / connection
• Tool Surface / Operation Registry
• Resume / Profile / Evidence
• browser job capture + Smart Fill
• QQ/163/Gmail/etc. read-only email sync
• progress candidates / stage events
• Memory Inbox / Learning Observation
• Today / Pipeline / Job / Profile

The remaining gap is primarily consumer productization and onboarding, not another broad capability wave.

Key product decisions proposed

1. Native installer is the default consumer entry point; no Python/Node/Git setup.
2. Existing local Agents are the default reasoning layer; built-in Agent remains fallback.
3. Resume + explicitly authorized local AI memory bootstrap Profile, but unverified memory stays candidate/evidence-first.
4. User-triggered current-page browser capture is the default job acquisition path.
5. Email intelligence creates reviewable progress candidates instead of silently mutating Pipeline state.
6. The next milestone is a repeatable Zero-Setup Golden Path, not a larger tool catalog.

Design slices

The document proposes five delivery phases:

• Zero-Setup shell
• Know Me / Profile T0
• First Opportunity / browser capture
• Progress Sync / mailbox
• Golden Path Beta

Each section includes target UX, data flow, trust boundary and Definition of Done.

References

• WorkDaddy — installer and automatic local-client discovery:
  https://github.com/babygoton/WorkDaddy
• career-ops — career workflow / human-in-the-loop apply:
  https://career-ops.org/
• Career Ops Capture — explicit current-page capture pattern:
  https://chromewebstore.google.com/detail/career-ops-capture/emnnnnjlecidladmnnjopelhipkomnaa
• boss-cli — research reference for BOSS capabilities, not the proposed default consumer ingestion path:
  https://github.com/jackwener/boss-cli

Scope

Docs only.

No Runtime, Operation Registry, Tool Surface, Eval, browser or email implementation is changed in this PR.

The goal is to align the product milestone and user journey before opening implementation slices.

[avabbbb]

Superseded by #20. The Zero-Setup onboarding goals from this PR are now incorporated into the current product authority at docs/product/current-product.md, with the rest of the repository documentation aligned around the same model. Closing this PR avoids two competing product-authority documents.