Refresh CLI resources and release Agentplugins 0.20.0

[b10x-bot]

Agentplugins' resources lagged the released CLI contracts, the current ESS tutorial failed its native conformance checks, and upgrades from a frozen local marketplace could not discover replacement plugins. This refresh targets Agentplugins 0.20.0 and makes the instructions, executable examples, installers and verification gates agree with the current releases.

• Verify AEP 0.68.0, ESS 0.53.0, Worktree 0.8.2, Metaharness 0.9.1, Connectors v0.28.0 and Docs System 0.7.0. Match the eval AEP binary to Metaharness's embedded source; install its actual runtime prerequisites.
• Replace the current ESS tutorial and fixtures with a Rust target that passes all 17 generated scenarios, including consistency/freshness checks. Add validated related-guard, selected-effect, transport, protocol and compatibility examples; retain dated historical walkthroughs.
• Teach current Connectors setup, acquisition, operation schemas/revisions and invocation. Install its source-only release from the exact tag and require the actual Rust compiler floor. Correct frozen-marketplace upgrades before updating plugins.
• Strengthen current-tool/upstream verification, command option parsing, generated-directory exclusions and Rust trial reporting. Preserve crashed/incomplete Cargo failures and separate scenario coverage from Cargo test counts.
• Refresh current public tutorials, trial prerequisites, setup/routing/maintenance guidance and aligned release metadata. Document partial-wave obligations and managed worktree recovery.

Validation: task check passes 155 tests; 17 eval definitions validate and one recorded transcript replays. The latest-tool gate passes, including an actual Connectors source installation, 17 native tutorial scenarios and the capability examples. Documentation typecheck, build and the exact CI source checker pass. Independent adversarial tests reject broken lifecycle guards, missing consistency tokens, unsupported/error targets, stale transport digests and the original verifier false greens. Native Claude/Codex marketplace-source probes preserve installed plugin state.

The nine-trial round and bounded managed-wave verification are detailed in changes/0.20.0-verification.md, including actual scenario counts, trial fixes and the retained historical baseline. The first governed-plan wave is partial feature delivery, not complete reservation-feature conformance. Paid live CI evals were not run.

Remaining external work: Atlas owns two generated documentation workflow pins and asynchronous documentation publication. The latest documentation packages retain 32 npm audit findings (30 high, two low) with no available direct-package fix. This PR does not claim a clean npm audit or publish downstream sites/releases.