fix(acp,daemon,serve): wire SelfCheckPipeline, TrajectorySentinel, and SkillInvokeExecutor into all entry points

[bug-ops]

Summary

• SelfCheckPipeline (config.quality.self_check), TrajectorySentinel (config.security.trajectory, spec-050), and SkillInvokeExecutor (invoke_skill tool) were each constructed and wired into the Agent only in src/runner.rs (CLI/TUI entrypoint) — another instance of the recurring "wire-X-into-ACP/daemon/serve" defect class (18+ prior confirmed instances in this codebase).
• Extracted agent_setup::build_quality_pipeline as a shared helper used by all four entry points (runner.rs, acp.rs, daemon.rs, serve), closing a future-divergence risk.
• Wired TrajectorySentinel config plus the paired PolicyGateExecutor/ScopedToolExecutor signal-queue plumbing into acp.rs (per-session), daemon.rs (process-wide), and serve/agent_factory.rs (per-session).
• Constructed and registered SkillInvokeExecutor in the ACP and daemon composite tool chains, sharing a trust_snapshot Arc with the Agent. Serve does not wire skill_loader/memory/overflow at all (separate pre-existing gap, tracked in serve /sessions* never wires skill_loader, memory, or overflow tools — confirmed pre-existing gap #6046) and is correctly out of scope for this fix.
• Added 9 regression tests covering reachability of each fix through the real production composite chains in acp.rs, daemon.rs, and serve/agent_factory.rs.

Known limitation (not fixed here)

Serve's ScopedToolExecutor ([security.capability_scopes] wrap) is built once, eagerly, and shared across every concurrent /sessions* agent — before any per-session trajectory signal queue exists. Attaching a per-session queue there would leak one session's OutOfScope signals into every other session sharing that executor. This is documented in code (gate_serve_session_executor's doc comment) and tracked as a follow-up in #6045. It is a bounded defense-in-depth gap, not a control bypass or a regression from baseline (serve had zero trajectory wiring before this PR).

Follow-up issues filed

• serve ScopedToolExecutor capability-scope denials never reach TrajectorySentinel signal queue #6045 — serve ScopedToolExecutor capability-scope denials never reach TrajectorySentinel signal queue (tracks the known limitation above)
• serve /sessions* never wires skill_loader, memory, or overflow tools — confirmed pre-existing gap #6046 — serve /sessions* never wires skill_loader, memory, or overflow tools at all (confirmed pre-existing gap, broader than just invoke_skill)

Closes #5951
Closes #5975
Refs #5958

Test plan

• cargo +nightly fmt --check
• cargo clippy --profile ci --workspace --all-targets --features "desktop,ide,server,chat,pdf,scheduler,testing" -- -D warnings
• cargo nextest run --config-file .github/nextest.toml --workspace --features "desktop,ide,server,chat,pdf,scheduler" --lib --bins — 12817 passed, 0 failed, 35 skipped
• RUSTFLAGS="-D warnings" RUSTDOCFLAGS="--deny rustdoc::broken_intra_doc_links" cargo doc --no-deps --workspace --features "desktop,ide,server,chat,pdf,scheduler"
• 9 new regression tests added (reachability through real production composite chains, not shallow/tautological)
• Adversarial critic review — no critical/blocking findings
• Code review — approved
• .local/testing/playbooks/ and coverage-status.md updated (main repo path)