fix(core): isolate internal/status observers

[tdwhere123]

Problem

Fiber._updateState emits internal/status with no isolation. A diagnostic observer that throws is caught by the Fiber constructor, written into _error, and can reject await plugin even when the plugin itself succeeded. The same throw also:

• overwrites a real plugin execution error, so FAILED is attributed to the observer
• aborts remaining internal/status listeners
• skips the reflect.notify that follows a transition into or out of ACTIVE
• turns a later _reload emit into an unhandled rejection when nobody awaits the Fiber

internal/plugin disposal observers already follow a log-only boundary (see #39). internal/status on current main does not.

Observation	Current main	This change
healthy plugin + throwing observer	await plugin rejects with the observer error	Fiber stays ACTIVE; observer is logged
plugin throw + throwing observer	await plugin rejects with the observer error	rejects with the plugin error; state is FAILED
two status observers, first throws	second observer never runs	second observer still runs
observer returns a rejected thenable	unhandled rejection	logged; Fiber stays ACTIVE

The five regressions fail on 8cc9e33 for those reasons and pass on this branch.

Change

Replace the unguarded emit('internal/status') with a local dispatchFiberStatus helper:

• resolve listeners through the existing events.dispatch path so thisArg/bind semantics stay the same
• catch each listener independently and report via ctx.logger.error
• observe thenable rejections without awaiting them
• leave reflect.notify on the success path after the broadcast

This does not change internal/plugin, internal/dispatch, or the Fiber generation/epoch machinery in #39 / #54.

Regression coverage

packages/core/tests/status.spec.ts covers the five rows above, including a provider/consumer case so a throwing observer cannot skip service notify.

Validation

• yarn lint
• yarn yakumo tsc
• yarn test cordis/status — 5 tests passed
• yarn test cordis — 13 files, 76 tests passed
• yarn test:json — 20 files, 168 tests passed
• git diff --check origin/main...HEAD — passed