feat(edge): harden fleet reporter delivery

[Jorel97]

Closes #24

/claim #24
Strengthens the Edge Reporter module for Fleet Manager / MoltClaw delivery while keeping the existing edge config shape intact.

What changed:

• Adds explicit Register() and SendHeartbeat() reporter methods so registration and heartbeat delivery can be tested directly.
• Adds ReportStatus() for structured node status snapshots at /fleet/status.
• Keeps ReportEvent() and PublishGene() behavior, but adds event type validation and deterministic timestamp plumbing for tests.
• Makes reporter shutdown idempotent and falls back to a sane heartbeat interval when config is zero or negative.
• Hardens HTTP delivery with trailing-slash-safe endpoint joining, bearer token authorization, injectable HTTP client, and response-body details on non-2xx failures.
• Documents Fleet Manager reporter endpoints in the README.
• Adds httptest coverage for registration, heartbeat with gene stats, status, events, gene publishing, authorization, failure details, validation, and idempotent stop handling.
• Includes a small deterministic pkg/gene tie-breaker fix so the repository-wide Go suite can pass while reviewing the bounty branch.

Verification:

• go test ./pkg/edge
• go test ./pkg/edge ./cmd/picoclaw
• go test ./...
• git diff --check

Reviewer note: after the maintenance update, the branch passed go test ./..., including pkg/edge, pkg/gene, and pkg/logger.

[Jorel97]

Maintenance update pushed after the issue-thread validation discussion:

• added deterministic gene-selection tie-breaks when candidate scores are equal (score desc, then confidence desc, then verification count desc)
• this removes the unrelated full-suite blocker in pkg/gene while leaving the Edge Reporter scope intact

Validation after the update:

• go test ./... -> passed, including pkg/edge, pkg/gene, and pkg/logger
• git diff --check -> passed

[Jorel97]

Validation refresh for bounty #24:

• PR body now explicitly uses Closes #24 for issue association.
• Re-ran validation on the current branch:
  • go test ./pkg/edge ./cmd/picoclaw -> passed
  • go test ./... -> passed
  • git diff --check -> passed

No contributor-side changes are pending unless maintainers want a different reporter API shape.