Fix production Docker build (glibc/musl mismatch)

[sympact06]

Problem

The production build fails with:

Error: Cannot find module '../lightningcss.linux-x64-musl.node'
Error: Could not load the "sharp" module using the linuxmusl-x64 runtime

Root cause

The development stage installs node_modules on node:lts (Debian, glibc), and the build stage (node:lts-alpine, musl) copies them over. Native binaries (lightningcss, sharp, @next/swc) are libc-specific, so the copied modules can't load on Alpine.

This never surfaced before because the build didn't actually load these native modules. After the dependency bump (Next 15.5, Tailwind 4.3) and the new CSS module from #205, it does.

Fix

Use node:lts-alpine for the development stage too, so all stages share the same libc and copying node_modules between them stays valid.

Also fixes a small npm flag typo: --omit:dev -> --omit=dev (it only worked by accident because NODE_ENV=production already omits dev deps).

Also included

Two pre-existing type errors in DrugInfo.tsx failed next build type-checking after the Docker fix, so they're fixed here too (types only, no behavior change):

• comboObject was cast to a map over all Status keys but omitted Status.Self. It's now typed as Exclude<Status, Status.Self> instead of adding a Self entry, because the render loop maps over Object.keys(comboObject) and comboColors has no Self entry (rendering it would crash).
• comboData[drugB] indexed the Interactions interface with a plain string; now uses keyof Interactions with a guard for the optional entries.

Verified with npx tsc --noEmit: 0 errors.