fix(web): route uninitialised-project refusals through the error screen

[cvince]

The systemic class, on the three paths a run actually proved.

console.error(); process.exit(1) in a guard never throws → the surrounding catch never runs → displayErrorAndExit never serves its page. rotateCommand.ts documents this class and its own fix; it was never applied elsewhere.

command	fix
checkout	throw into the catch that already routes correctly
decrypt	same
branch	not inside a try, so it calls displayErrorAndExit directly — that function reads web mode itself, so no flag plumbing

Framed against the invariant — a URL reaches the caller. Nothing asserts loopback, so moving the renderer to Keep will not rewrite these tests.

Two commands I nearly reported as broken, and did not

The control caught both:

• kick — kick --web never reaches a guard; Commander rejects it first with missing required argument 'email'.
• checkout — checkout --web with no branch name does the same. The first draft of this file ran exactly that, saw output with no URL, and would have filed a violation that does not exist. Passing somebranch reaches the real guard, which was genuinely broken and is fixed here.

Both failed on "did it reach its refusal", not on "was there a URL". A test that asserts an absence without first proving the command arrived is a test that invents defects — this file would have invented two.

transport, edit and org are absent for the opposite reason: their runs get past the guard into the auth path and do hand back a URL. A source sweep lists them; running them clears them.

Observed, not inferred

$ capy checkout somebranch --web
  No keep.lock file found. Run capy first to initialize the project.

  What went wrong is in your browser:
  http://127.0.0.1:49657/s/b1MgZXtmUTkd3O6r5hynn0Mg2NRkc9tfHoQ7wyk1Otg

Suite: 1847 pass, 0 fail.