karpenter: parseRam: Accept decimal and Pi/Ei quantities

[RajPrakash681]

Summary

parseRam matched memory quantities against /^(\d+)([KMGT]i?)?$/i, which rejects two valid forms and returns 0 for both:

• Decimals. 1.5Gi has no digit-only mantissa, so a NodePool with spec.limits.memory: 1.5Gi showed its limit as 0. Because the callers treat limit > 0 as "a limit exists", the view then reported "No limit" for a NodePool that has one, and the percentage bar was scaled against a total of 1 byte.
• Pi and Ei. The unit group stopped at T, so 2Pi returned 0.

The suffixes that did parse were also scaled with the wrong base. Kubernetes reads a suffix without i as a decimal multiple and one with i as binary, so 1G is 10^9 bytes while 1Gi is 2^30. The old map sent both to 1024^3, making unsuffixed limits read about 7% high.

Related Issue

Fixes #1245

Changes

• parseRam now accepts an optional fractional part, covers P and E, and picks base 1000 or 1024 from the presence of the i suffix. Unparseable input and an unknown unit still return 0, and i is only accepted when it follows a unit.
• Added karpenter/src/helpers/parseRam.test.ts covering decimals, Pi/Ei, the decimal-versus-binary distinction, plain byte counts, and the unparseable cases. Three of the five fail against the previous implementation.

I did not switch to the SDK's parseRam from @kinvolk/headlamp-plugin/lib/lib/units: it handles Pi/Ei and the base correctly, but in the pinned 0.14.0 it takes the mantissa from a leading-digits match, so 1.5Gi comes back as 1 instead of 1610612736. That is better than the current 0 but still wrong, so fixing the local helper avoids trading one bug for another.

Steps to Test

1. cd karpenter && npm install && npm run test — the five parseRam cases pass.
2. npm run lint && npm run tsc — both clean.
3. Check out main for karpenter/src/helpers/parseRam.tsx only, keeping the test file, and re-run: the decimal, Pi/Ei, and decimal-multiple cases fail.
4. Against a cluster running Karpenter, apply a NodePool with spec.limits.memory: 1.5Gi and open Karpenter → NodePools. The Memory column reads 1.5Gi with a scaled bar instead of 0 (No limit).