fix: stop passing a skills allowlist to Claude Code sessions

[SawyerHood]

Problem

Using any user-installed skill (e.g. from ~/.claude or a Claude Code plugin) inside a bb-managed Claude Code session fails with:

Skill frontend-design is not in this session's skills allowlist

The claude-code adapter forwarded bb's injected skill names as the Agent SDK skills option. Per the SDK docs, skills: string[] enables only the listed skills — a session-wide allowlist that hides and rejects everything else. The plumbing shipped in 8d02034 but only activated when injected skills existed; once 5f87c16 bundled building-bb-apps as a builtin injected skill, every session ran with the allowlist set to just the injected skills, breaking user-installed skills everywhere.

The allowlist was never needed: injected skills load as a local plugin via the SDK plugins option, and plugin skills are enabled by CLI defaults. (settingSources already includes user, so ~/.claude skills were discovered all along — just rejected at invocation.)

Fix

Remove the allowlist end-to-end rather than leave dead plumbing (accepted-but-ignored fields are forbidden):

• adapter: buildClaudeSkillConfigParams emits plugins only, with a comment pinning why skills must never be set here
• bridge: drop skills from the thread/start + thread/resume schemas, BuildSessionOptionsArgs, SdkSessionOptions, and the query() call
• runtime: drop skillNames from AgentRuntimeClaudeCodeSkillRoot and its normalization
• host-daemon: staging no longer attaches skill names to the claude-code skill root (plugin.json still lists them, which is what enables them)

Codex and pi adapters are additive ("extra roots") and were never affected.

Tests

• Regression pins at three layers (adapter command params, buildSessionOptions, SdkSession.start query options) assert no skills allowlist reaches the SDK
• Existing integration test still verifies injected plugin skills are usable per provider
• turbo run typecheck + test for @bb/agent-runtime (567 tests) and @bb/host-daemon (386 tests) pass

🤖 Generated with Claude Code