Import swap to the satellites and the got upgrade #40

Parent

Spec: #33 (Baseline release). Section numbers refer to its Implementation Decisions.

What to build

wand's runtime graph uses the Satellite modules, and the test framework no longer ships in user binaries: a program importing wand links no got. The suite is unchanged apart from import lines. Spec section 6; ADR-0006.

Acceptance criteria

• goob to eventbus, gson to lazyjson (every import; exported signatures and protocol fields now name lazyjson.JSON), gotrace to leakcheck (test files and the proto test generator where relevant), got's LCS to seqdiff in the page package's DOM-stable wait.
• got and gop upgraded to their latest versions and present only in test files; the Gate's coverage-checker pin updated to match.
• go mod why shows no ysmood/* module reachable from non-test packages except fetchup and leakless, which later tickets remove; a program importing wand builds without got in its binary.
• The suite passes on the Gate with no test logic changed; coverage stays at 100 %.

Blocked by

• Package layout: internal/, cmd/, tools and docker/ #35 (Package layout: internal/, cmd/, tools and docker/)
• Four snapshot satellites: eventbus, lazyjson, seqdiff, leakcheck #38 (Four snapshot satellites: eventbus, lazyjson, seqdiff, leakcheck)