fix: report site/adapter-source command errors cleanly instead of crashing

[ayushsingh82]

Summary

Working through the local-mode portion of the manual QA checklist in #311, I found that every webcmd site * subcommand (notes, endpoints, field-maps, fixtures, samples) and webcmd adapter source get/put / adapter path had no error handling in their commander actions. Any failure — a missing fixture, an invalid site name, a duplicate field-map key, an unsupported local write — surfaced as a raw unhandled-rejection stack trace instead of the CLI's normal Error: ... output, and always exited 1 regardless of the error's intended exit code (e.g. SITE_MEMORY_NOT_FOUND should exit 66, an ArgumentError should exit 2).

• src/site-memory/commands.ts (shared by local and hosted mode via registerSiteCommands) — added a wrapAction helper so every action reports errors and exit codes consistently.
• src/cli.ts — same fix for adapter source get, adapter source put, and adapter path.
• src/cli.test.ts — updated 3 pre-existing unit tests that had encoded the old crash-and-reject behavior as expected, to instead assert the clean error message + correct process.exitCode.
• tests/e2e/adapter-authoring-parity.test.ts (new, registered in vitest.config.ts) — e2e coverage for the local-mode-testable sections of test: validate adapter authoring and override parity in local and hosted modes #311: mode boundaries, override/source/reset workflow, site memory + fixtures + samples, browser init/verify and its flags, and mutable input-output files via a private test adapter.

Sections of #311 requiring a live hosted Cloud deployment (workspace/user isolation, marketplace metadata) are out of scope here — this addresses the local-mode reliability gap surfaced while working through the checklist.

Test plan

• npm run typecheck
• npm test (unit + plugin, 5589 passed)
• npx vitest run --project e2e tests/e2e/adapter-authoring-parity.test.ts (28 passed)
• Manually verified before/after CLI output for site fixture get (missing → clean error, exit 66), site note add ../evil (clean error, exit 1), adapter source get --output (clean error, exit 2)

[ayushsingh82]

@beubax mind taking a look? Quick summary of what's here:

Working through the local-mode checklist in #311, every webcmd site * subcommand (notes, endpoints, field-maps, fixtures, samples) and webcmd adapter source get/put/adapter path turned out to have no error handling — any failure surfaced as a raw unhandled-rejection stack trace and always exited 1, discarding the intended CliError exit code (e.g. a missing fixture should exit 66, a bad flag 2). This PR fixes that in site-memory/commands.ts (shared by local and hosted mode) and the adapter-source actions in cli.ts, updates the 3 unit tests that had encoded the old crash as expected behavior, and adds e2e coverage (tests/e2e/adapter-authoring-parity.test.ts) for the local-mode-testable portion of #311's checklist.

Full details and test plan are in the PR description above. Happy to adjust scope if you'd rather this land as smaller pieces.

[github-actions]

🟠 Maintainer review suggested — low confidence

The automated review could not reach a fully supported conclusion.

Limitations

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This review is advisory and does not block merging.