Panel presets make full-year a Store-facing offer before its gates pass

[lamemustafa]

Raised as a P1 on #169. Filed rather than fixed there: the finding is correct, but how to gate it is
a product decision, and the mechanism does not exist yet.

What

src/entrypoints/panel/panel-presets.ts offers one whole-financial-year preset per return type. The
popup links to panel.html, and the package verifier now requires that page in every build — so a
Store package carries a full-year download offer for every return type, including GSTR-2B.

docs/PUBLICATION_READINESS.md holds full fiscal year as source-build alpha, limited to eligible
GSTR-3B/GSTR-1 periods, and states that Store-facing V0 must not advertise it until the exact-ZIP,
restart/resume, reconciliation and privacy gates are recorded. Those gates are not recorded.

My error, recorded

I ticked "Full fiscal year remains source-build alpha and is not part of the Chrome Web Store V0
listing" on #169's body. That claim is false for the PR as it stands, and I asserted it without
checking it against what the panel offers. The checkbox has been corrected.

The decision

There is no build-time gating mechanism in the repository today, so this needs one of:

1. Restrict the presets to the scope the alpha already covers — eligible GSTR-3B/GSTR-1 periods —
   so the panel offers only what the readiness document permits. Smallest change; no new mechanism.
2. Gate the panel entrypoint out of Store packages behind a build flag. Larger, and introduces a
   build-variant concept that does not exist and would need its own verification, since a package
   gate that silently fails open is worse than none.
3. Record the gates, which is the real work and not a packaging change.

Option 1 is the cheapest honest outcome and keeps one build. Option 2 buys more but adds a mechanism
whose failure mode is exactly the kind this repository guards against.

Note for whoever takes this

The package verifier now requires panel.html, so removing the page from a build would fail
verification. Any gating approach has to update that expectation deliberately rather than tripping
over it.

[lamemustafa]

Half of this issue's premise has dissolved; the other half stands, and is now sharper for it.

What changed. This issue rests on a contradiction: docs/PUBLICATION_READINESS.md held full fiscal year as source-build alpha, while the Store package shipped a panel offering it. #192 corrected that record — full-year is now stated as shipping in the one binary and simply not Store-advertised, which was already the decision recorded two entries below it. The listing says the same. So the readiness document no longer contradicts the package.

What remains. The narrower question this issue was really about: the panel offers a whole-financial-year preset for every return type in a Store build, while full-year has not passed its four evidence gates. Correcting the paperwork did not change what the panel offers, and "ships but is not advertised" is a claim about copy, not about what the UI puts in front of a user.

So the open decision is unchanged and now unambiguous: should a Store build present an offer for a workflow whose gates are unrecorded? That is a product call, and #192 removed the documentation confusion that was obscuring it.

One thing that has moved for GSTR-2B specifically. #196 and #199 gave GSTR-2B full-year a real artifact — an invoice-level workbook with an ITC summary — verified against a captured year. That strengthens the case for the offer existing and does nothing for its evidence gates, which are still what this issue is about. Worth separating those two when the decision is made: the feature working is not the feature being evidenced.

No change proposed; recording the premise shift so the issue is not read against a document that no longer says what it quotes.