Improve plugin install/init error handling

[pggdev]

SUMMARY

Make plugin installation and event handling safer by isolating plugin failures and using one consistent plugin:error payload across the runtime.

SCOPE

• Plugin registration/install failure isolation

• Event listener failure isolation during dispatch

• Standardized plugin:error payload (additive, non-breaking)

• Replace index-based plugin event usage with explicit constants

• Tests for all above runtime error paths

• Integration-layer alignment to avoid inconsistent/duplicate error emission

TASKS

Add failure-first tests for plugin runtime behavior

• Add test: plugin install() throws, manager still works

• Add test: failed plugin is not stored

• Add test: healthy plugin still registers after a failed one

• Add test: plugin:error is emitted with expected fields

• Add test: if one listener throws during emit(), other listeners still run

Define canonical PluginErrorPayload (additive type)

• include: source, phase, pluginName, message, cause, recoverable, timestamp (+ optional eventName)

Replace index-based plugin error event usage

• add explicit plugin event constants

• remove runtime dependence on PLUGINEVENTS[1]

Harden PluginManager error boundaries

• wrap plugin.install(api) in try/catch

• emit canonical plugin:error on install failure

• register plugin only after successful install

• guard each listener invocation during emit() and continue dispatch

Align Standalone.tsx error emission

• avoid duplicate plugin:error emission for the same failure path

I'm happy to open a PR for this issue.

[github-actions]

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[pggdev]

@AceTheCreator @TenzDelek, should i proceed with this issue?