v0.7.0: RED→GREEN for scroll-notify + autocomplete

Properly followed TDD cycle:
- Reverted implementations, proved RED (3 assertions fail)
- Re-added implementations, proved GREEN (3 assertions pass)
- Recorded both outputs in org files

docs/DESIGN_DECISIONS.org

@@ -462,4 +462,16 @@ The critical risk is implementation: achieving the retrieval precision, Dispatch
 
 6. *The self-repair criterion.* "What belongs in core?" is decided by a single test: if this file is corrupted, can the agent fix it without human help? Corrupted core = dead brain, dead hands, or unreachable. Corrupted skill = degraded but self-repairable. If the agent has tools, identity, and user input, it can reason about missing awareness, edit the corrupted source file, reload the skill, and continue. If it loses its own reasoning loop, it has no way to self-diagnose. This is why context assembly and heartbeat generation were extracted to skills in v0.5.0 — the agent can detect their absence and reload them. The core contracts to the absolute minimum needed for self-repair: the pipeline, the memory, the transport, and the skill loader.
 
+7. *Why no subagents?* Claude Code, OpenCode, OpenClaw, and Hermes all implement multi-agent delegation (parent spawns child with separate context, tools execute, child reports back). Passepartout rejects this on principle. There are five reasons:
+
+   *Zero coordination overhead.* Subagents spend tokens on delegation protocols — prompt templates for spawning, agent-summary messages for progress reporting, sidechain transcripts for integration. Passepartout's single-brain model pays zero tokens for inter-agent communication.
+
+   *Causal traceability.* Every decision traces through a single Merkle chain, a single gate stack, a single memory space. With subagents, if a delegated agent makes a bad decision, the parent agent may never see the full reasoning — the subagent's internal context is opaque.
+
+   *Memory coherence.* Subagents require either duplicated context (wasteful) or context partitioning (lossy). Passepartout's foveal-peripheral model sees everything relevant in a single memory space — there is no context to split.
+
+   *The arXiv paper (2604.14228v1) validates this.* Section 11.3 notes that subagent isolation is a genuine trade-off: "Isolated subagent boundaries" vs unified memory coherence. The paper treats both as legitimate architectural choices.
+
+   *When would subagents be warranted?* If Passepartout ever needs to execute background tasks that don't share the main agent's context (e.g., nightly cron jobs, cross-project analysis), the architecture can add isolated agents as a skill — not as a core mechanism. The single-brain model is the default, not the only option.
+