feat: apply default resource requests and limits to TimeSeries, Search, and Server components

[digiserg]

Summary

When users create an AxonOpsPlatform CR without specifying resources on the TimeSeries, Search, or Server components, the resulting containers run with no CPU/memory requests or limits (best-effort QoS
class). This causes unpredictable scheduling, OOM kills under memory pressure, and noisy-neighbour interference in shared clusters. This issue adds sensible default resource requests and limits derived from
each component's runtime characteristics, applied only when the user has not specified their own.

Dashboard defaults are explicitly out of scope for this issue.

Requirements

Heap size parser

Add a helper parseHeapSizeMi(heapSize string) (int64, error) that:

• Accepts M/m (MiB) and G/g (GiB) suffixes: "1024M" → 1024, "2g" → 2048
• Rejects empty string, no suffix, bad suffix, decimals, zero, negative values

Default resource computation

TimeSeries and Search (JVM): memory = int64(heapMi * 1.5) MiB req/limit; CPU request 1000m, no CPU limit. Falls back to component default heap on parse error with a V(0) warning.

Server (Go): memory request 256Mi, limit 512Mi; CPU request 250m, no CPU limit.

Application logic

Applied only when component.Resources.Requests == nil. No CRD schema changes. No webhook. Dashboard explicitly excluded.

Acceptance Criteria

1. TimeSeries with no resources → 1536Mi memory req/limit, 1000m CPU req, no CPU limit
2. TimeSeries with heapSize: "2048M" → 3072Mi memory
3. TimeSeries with heapSize: "invalid" → falls back to 1536Mi
4. TimeSeries with explicit resources → user values preserved verbatim
5. Search with no resources → 3072Mi memory req/limit, 1000m CPU req, no CPU limit
6. Search with heapSize: "4096M" → 6144Mi memory
7. Search with heapSize: "invalid" → falls back to 3072Mi
8. Search with explicit resources → user values preserved verbatim
9. Server with no resources → 256Mi req, 512Mi limit, 250m CPU req, no CPU limit
10. Server with explicit resources → user values preserved verbatim
11. parseHeapSizeMi unit tests pass for valid and invalid inputs
12. No public API signature changes
13. No data race (go test -race)
14. Dashboard resources unchanged
15. make lint passes

Testing Requirements

• TestParseHeapSizeMi_ValidInputs and TestParseHeapSizeMi_InvalidInputs (table-driven)
• TestParseHeapSizeMi_ArbitraryString_NeverPanics (property-based, testing/quick)
• Envtest: TestEnsureTimeseriesStatefulSet_DefaultResources_AppliedWhenOmitted, _CustomHeap_ScalesMemory, _InvalidHeap_FallsBackToDefault, _UserResources_NotOverridden
• Envtest: same 4 variants for Search and 2 for Server
• TestDashboardResources_Unchanged
• BDD: test/bdd/default-resources.feature already exists with 15 scenarios

Documentation Requirements

• Godoc on parseHeapSizeMi
• CHANGELOG Added entry describing the defaults
• Helm values.yaml comments on timeSeries.resources, search.resources, server.resources

Dependencies & Blockers

• Blocked by: nothing
• If refactor: split axonopsplatform_controller.go into component files (3618 lines) #77 lands first, implementation locations change but logic is identical
• No new Go modules needed