Finish axios migration via shared native HTTP helper

Replace all in-scope axios callsites with a new helpers/http.js wrapper over native fetch, including JSON/text GET, JSON POST, HEAD checks, and transient 5xx retry behavior; update all browser, build, script, and proxy API clients to use it; add focused unit tests; and remove axios from package dependencies.

Constraint: Preserve API/build and deployment behavior while lowering transport surface area.

Rejected: inline fetch replacements at each callsite | rejected to avoid inconsistent error/retry semantics.

Confidence: high

Scope-risk: moderate

Directive: Keep helper in place as the transport boundary and update tests when changing request semantics.

Tested: pnpm run -s typecheck, pnpm -s run test-prebuild, pnpm -s run test, pnpm -s run test:browser, pnpm -s run netlify-build, smoke GETs on /apple-silicon-app-test and /apple-silicon-app-test/?version=2

Not-tested: branch/netlify deployment health in CI pipeline after merge

helpers/build-game-list.js

@@ -1,8 +1,7 @@
-import axios from 'axios'
-
 // import { statuses } from './build-app-list'
 import { getAppEndpoint } from './app-derived'
 import { makeSlug } from './slug.js'
+import { getJson } from './http.js'
 
 
 // console.log('process.env.GAMES_SOURCE', process.env.GAMES_SOURCE)
@@ -68,11 +67,10 @@ function parseStatus(game) {
 export default async function () {
 
     // Fetch Sheet data
-    const gamesSheet = await axios
-        .get(process.env.GAMES_SOURCE)
+    const gamesSheet = await getJson( process.env.GAMES_SOURCE )
         .then(function (response) {
             // handle success
-            return response.data.records
+            return response.records
         })
         .catch(function (error) {
             // handle error