zeph_subagent::filter_skills applies no trust filter at all

[bug-ops]

Description

Found by impl-critic (M4) during review of PR #6712 (#6707/#6706 fix). zeph_subagent::filter_skills (crates/zeph-subagent/src/filter.rs:503) builds a subagent's visible skill list with no trust-level filtering whatsoever — Blocked and Quarantined skills alike are passed through unfiltered. This is unrelated to the #6710/#6701 fix (which addressed active_skill_names/matching in zeph-core's assembly.rs) and unrelated to #6712's mention-picker fix (skill_catalog_items, also zeph-core) — this is a separate code path in zeph-subagent.

#6706's original complaint ("an AutoSkill draft... will still surface in matching and be reported to the user/subagent as an available skill by name") explicitly named the subagent listing surface, but neither #6710 nor #6712 touched zeph-subagent.

Reproduction Steps

1. Have a skill with Blocked or Quarantined trust in the registry.
2. Spawn a subagent whose skill visibility is built via zeph_subagent::filter_skills.
3. Inspect the skill list the subagent receives.

Expected Behavior

filter_skills should apply the same trust-aware filtering as the parent-agent surfaces it: at minimum, exclude Blocked (and, per the resolution converged on in #6710/#6712, either exclude or annotate Quarantined consistent with whatever listing surface filter_skills feeds).

Actual Behavior

No trust filter is applied — Blocked and Quarantined skills appear identically to Trusted ones in the subagent's skill list.

Environment

• Version/commit: main, as of 2026-07-28 (post fix(skills): stop a proactively-matched Quarantined skill from locking a turn's tools #6710, pre-fix(skills): stop quarantined skill trust from escalating on relocation #6712)

Related

• fix(skills): stop a proactively-matched Quarantined skill from locking a turn's tools #6710 (closed Proactively-matched Quarantined skill locks the whole turn (and every spawned subagent) out of bash/write/MCP tools #6701, fixed matching/catalog-annotation in zeph-core's assembly.rs)
• fix(skills): stop quarantined skill trust from escalating on relocation #6712 (fixed mention-picker exclusion in zeph-core's skill_catalog_items)
• Quarantined skills still load, get catalog-listed, and get matched — trust only gates dispatch #6706 (original issue naming the subagent listing surface, now fully closed by fix(skills): stop a proactively-matched Quarantined skill from locking a turn's tools #6710+fix(skills): stop quarantined skill trust from escalating on relocation #6712 for the zeph-core paths; this issue tracks the missed zeph-subagent path)