chore(worker): wire up real KV ID + workers_dev=true + harden getNextRef

- wrangler.toml: workers_dev=true (= explicit routing on *.workers.dev)
- wrangler.toml: real KV ID c02656ba2206... after `wrangler kv namespace create WELCOME_KV`
- hubspot-proxy.js getNextRef: guard `!res.ok` before res.json() to surface HubSpot errors
- .gitignore: ignore .wrangler/ local cache dir

Discovered during Phase D2-D3 deploy + smoke testing.

Refs: WordPress \xe2\x86\x92 static migration plan, Phase B PR #3a.

cloudflare-worker/.gitignore

@@ -0,0 +1 @@
+.wrangler/

cloudflare-worker/hubspot-proxy.js

@@ -297,6 +297,9 @@ async function getNextRef(token) {
       limit: 100,
     }),
   });
+  if (!res.ok) {
+    throw new Error(`HubSpot search failed: ${res.status}`);
+  }
   const data = await res.json();
   let maxNum = 0;
   (data.results || []).forEach(c => {

cloudflare-worker/wrangler.toml

@@ -1,11 +1,12 @@
 name = "mva-hubspot-proxy"
 main = "hubspot-proxy.js"
 compatibility_date = "2026-04-01"
+workers_dev = true
 
 # KV namespace — placeholder ID, populated at deploy time (Phase D3)
 [[kv_namespaces]]
 binding = "WELCOME_KV"
-id = "REPLACE_AT_DEPLOY_TIME"
+id = "c02656ba22064923ab1c6db06b0f4a56"
 
 # Required secrets to configure via `wrangler secret put` :
 # - HUBSPOT_TOKEN