chore: scrub instance details and personal data from committed artefacts

Blood-pressure fixtures in the in-target integration suite were copied
from live readings; they are now synthetic with the same in/out split so
every assertion holds. Hard-coded operator hostnames move behind env vars
(DEPLOY_LOGS_URL, HEALTHLOG_PROD_URL), the codex client identifies via
the public repository URL, the OpenAPI servers entry points at a neutral
example host, and remaining workflow, docs and comment references to the
operator's instance or working notes are generalised. The compose
whitelist also gains DEPLOY_WEBHOOK_SECRET, which was missing and made
the deploy webhook unusable on compose installs.

src/lib/openapi/registry.ts

@@ -52,7 +52,10 @@ const openApiBase: Pick<
     contact: { name: "HealthLog", url: "https://healthlog.dev" },
   },
   servers: [
-    { url: "https://healthlog.bombeck.io", description: "Production" },
+    {
+      url: "https://healthlog.example.com",
+      description: "Your self-hosted instance",
+    },
     { url: "http://localhost:3000", description: "Local dev" },
   ],
   tags: [