feat: add /adopt discovery and native Agent Skills

[naraen-ram]

Purpose

Add the first complete /adopt workflow for discovering resources from existing OpenCode, DSH, Claude Code, and Pi installations without executing discovered code. This also adds immutable source acquisition and native installation for standards-compliant Agent Skills.

Fixes

N/A

Approach

• Add strict, dependency-free adoption RPC, capability, manifest, pagination, and error contracts.
• Discover supported resources through bounded, data-only ecosystem adapters.
• Expose discovery and inspection through the daemon, SDK, CLI, TUI, and web client.
• Acquire local, npm, and Git sources into immutable, content-addressed revisions without lifecycle execution.
• Validate archives, dependency locks, paths, source hashes, licenses, notices, and executable surfaces before publication.
• Render a hash-bound trust review containing the source identity, destination scope, resources, capabilities, executable helpers, conflicts, and precedence changes.
• Bind activation approval to the exact review, policy generation, immutable revision, and registry generation.
• Install valid Agent Skills through immutable registry pointers rather than mutable source directories.
• Preserve skill references and assets, reject unsafe executable helpers, and reject Pi disable-model-invocation skills until manual-only activation is supported.
• Persist native adoption operations across daemon restarts and reload affected sessions only at safe boundaries.
• Bump the wire protocol from version 17 to 18 for the expanded adoption contract.

Security impact:

• Discovered source remains untrusted data and is never imported or executed.
• Credentials and sensitive paths are rejected before immutable publication.
• Source mutations, stale approvals, registry races, collisions, unsupported primary surfaces, and unavailable isolation fail closed.
• Adopted skills are loaded only from verified immutable revisions selected by the daemon-owned registry.

How was this tested?

Passed:

• pnpm build
• pnpm --filter @axl/compiler test — 48 tests passed
• pnpm --filter @axl/protocol test — 57 tests passed
• pnpm --filter @axl/extension-skills test — 5 tests passed
• pnpm --filter @axl/runtime test — 15 tests passed
• pnpm --filter @axl/sdk test — 64 tests passed
• pnpm --filter @axl/web test — 45 tests passed
• pnpm --filter @axl/tui test — 209 tests passed in the focused package run
• node --test packages/daemon/test/adoption-store.test.ts — 19 tests passed
• node --test --test-name-pattern='reload rebuilds|dispatches cancellable adoption' packages/daemon/test/daemon.test.ts — 2 focused tests passed
• pnpm typecheck
• pnpm lint
• pnpm check:boundaries
• pnpm check:generated
• pnpm audit --audit-level high — no known vulnerabilities
• Changed-file Biome formatting checks

Additional review:

• Independent adversarial review completed with no remaining critical, high, medium, or low findings.

Aggregate-suite note:

• pnpm test reached 1,029 tests but failed on two existing timing-sensitive checks: the TUI stale-shutdown test and the release-package test's fixed 30-second timeout.
• The TUI stale-shutdown test passed independently.
• node --test --test-timeout=120000 scripts/build-release-package.test.ts passed independently in about 37 seconds.
• reuse lint was not run because reuse is not installed in this environment.
• Repository-wide pnpm format:check remains blocked by pre-existing unrelated formatting changes in packages/ai/tsconfig.json and .vscode/settings.json; all files changed by this branch pass Biome.

Learning

• A discovery fingerprint is not a substitute for an immutable source hash. Native activation revalidates against the published immutable revision.
• Human review can outlive short discovery-cache windows, so review snapshots need a user-scale lifetime while still revalidating source content.
• Registry activation is authoritative. Session reload requests must be coalesced by registry generation and retried at safe boundaries.

Checklist

• I reviewed the complete diff.
• I added or updated the smallest relevant test for behavior changes.
• I ran the relevant build, type check, lint, test, boundary, and license checks, except reuse lint, which is unavailable as noted above.
• Every new file has SPDX metadata, directly or through REUSE.toml.
• Every commit has a matching DCO Signed-off-by trailer.
• UI changes include screenshots attached to the pull request, not committed to the repository.

AI assistance

• Generative AI materially assisted this change. Tool and model/version: Pi coding agent with azure-openai-responses/gpt-5.6-sol.
• I manually reviewed, understood, and tested the generated work.