docs(acp): annotate build_acp_deps with ignored config sections per spec 013

[bug-ops]

Context

.local/specs/013-acp/spec.md now contains a canonical "Config Coverage" table
that defines which config sections are active and which are intentionally ignored
in ACP mode (see the ## Config Coverage section).

The spec requires that build_acp_deps() and spawn_acp_agent() in src/acp.rs
contain an explicit comment block mirroring the "Ignored" rows of that table.

Required Change

Add the following comment block at the top of build_acp_deps() in src/acp.rs:

// Config sections intentionally not applied in ACP mode (see .local/specs/013-acp/spec.md):
//   [skills.learning]  — self-learning requires session feedback loop; judge_provider is
//                        built but .with_learning() is intentionally not called
//   [index] / [lsp]    — code indexing and LSP hooks are CLI/TUI interactive features
//   [agents]           — subagent delegation not supported in ACP sessions
//   [orchestration]    — DAG planner not wired for ACP
//   [cost]             — cost tracking not applied; ACP clients manage their own budgets
//   [experiments]      — benchmarking not applicable in ACP mode
//   [gateway]          — HTTP webhook ingestion is spawned by runner.rs, not per-session
//   [telegram/discord/slack] — ACP uses LoopbackChannel; external channels do not apply
// Scheduler: executor is wired, but --scheduler-disable / --scheduler-tick CLI flags
//            are not forwarded — use config fields only.

Acceptance Criteria

• Comment block is present in build_acp_deps() listing all ignored sections with reasons
• Comment block is consistent with the "Config Coverage" table in .local/specs/013-acp/spec.md
• No code behavior changes — annotation only

Files

• src/acp.rs — build_acp_deps() (~line 213), spawn_acp_agent() (~line 500)
• Reference: .local/specs/013-acp/spec.md § Config Coverage