Delete the decisions and design logs; scripts, rigs and xtask off the root

Iris: "remove both decisions and iris.md. I've decided to instead make
decisions when planning with agents rather than after they do things, and
they're both too long for me to wanna read, + don't cover all the
decisions I'll wanna make about the code anyways. I'll just naturally run
into things for now. Todo is important though."

So docs/DECISIONS.md (850 lines) and docs/IRIS.md (1,986) are gone, and
AGENTS.md now says not to start another: raise a choice while planning it
with her, otherwise decide it and put the reasoning at the code it
governs. The TODO lists stay. docs/SUBAGENTS_DECISIONS.md went with them
-- same artefact, same reasoning, and she did not name it, so its six
decisions were folded into docs/SUBAGENTS.md rather than deleted.

Deleting the logs left ~30 citations dangling in code comments and docs.
Each states its reason inline and cited the file only for provenance, so
they now read "decided 2026-09-07" or name the module doc that carries
the reasoning.

The root had six things that were not a program or a document. Moved,
per "I only meant top level sh files":

  run-tests.sh, test-wg-tunnel.sh, wg-setup-host.sh  -> scripts/
  rigs/                                              -> scripts/rigs/
  xtask/                                             -> scripts/xtask/

A project's own scripts stayed with the project: app/*.sh, app-rust/*.sh,
iris/*.sh and server/enroll-link.sh did not move.

`target/` at the root is deleted and cannot come back: there was never a
workspace there, and the 29 MB was only xtask's scratch space, now in
scripts/xtask/target/. `cargo xtask apk` still runs from the repo root
and now publishes to scripts/build/outputs/apk/<mode>/ -- one directory
deep, because that is what Dev Updater's `*/build/outputs/apk/*/*.apk`
discovery pattern needs, and scripts/xtask/build would have been two.

Verified: ./scripts/run-tests.sh and `cd iris && cargo test` green, clippy
and fmt clean everywhere, `cargo xtask apk debug --abi x86_64` builds and
signs an APK carrying lib/x86_64/libai_app.so at the new publish path, and
the repo root is now eleven entries with no build output among them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/SUBAGENTS.md

@@ -3,7 +3,7 @@
 A session's subagents -- the helpers a Claude Code session starts through its
 Task tool -- each get a transcript of their own, listed under the session's
 card and readable in the same transcript view the session has. Designed
-2026-09-05; the decisions Bryan has not yet reviewed are in `SUBAGENTS_DECISIONS.md`.
+2026-09-05; the choices behind it are at the bottom of this file.
 
 ## What a subagent is here
 
@@ -139,3 +139,43 @@ The per-subagent status is only read when the list route is asked for.
   cache take a transcript address rather than a session id --
   `sessions/{id}` or `sessions/{id}/subagents/{sub}` -- so the cache nests a
   subagent's copy under its session's and the same code serves both.
+
+## The choices behind the shape, and what they rejected
+
+
+Made without asking, each with limited blast radius:
+
+1. **A subagent is a transcript, not a session.** It has no process,
+   controls or settings; it is addressed as `/sessions/{id}/subagents/{sub}`
+   and stored under the session's directory, so deleting the session takes
+   it. Alternative rejected: registering it as a session of its own, which
+   would give it a card in the main list and a driver that can do nothing.
+2. **Read-only view is the session screen minus its controls**, rather than
+   a second, simpler transcript screen. Keeps paging, caching, selection
+   and rendering in one place. Cost: a `readOnly` mode threaded through
+   `SessionScreen`.
+3. **The list only carries a count.** Each session row says how many
+   subagents it has; their titles and statuses are fetched when the card is
+   expanded. Keeps `GET /sessions` from reading every subagent transcript.
+   Consequence: an expanded card's statuses refresh with the list, not live.
+4. **Expanded/collapsed is remembered per session on the phone**, not on
+   the server. Collapsed by default, per the transcript convention that new
+   things arrive collapsed.
+5. **Subagents of imported sessions are not shown.** The import path still
+   skips `isSidechain` records; the CLI's own `subagents/agent-*.jsonl` files
+   are not read. Only subagents run while this backend was watching exist.
+6. **Echo grows `/subagent [n]`** as the test rig, so nothing here needs a
+   paid turn to exercise.
+
+Deferred, because they reach further than this feature:
+
+- **Live status on the list.** Whether the session list should follow a
+  stream at all (it refreshes on demand today) decides whether subagent
+  status can ever be live there. Not changed.
+- **Nested subagents.** A subagent's own Task calls are shown as tool calls
+  in its transcript and are not given transcripts of their own. Supporting
+  that is the same mechanism one level down, but the UI would need nested
+  expanders.
+
+- **The subagent status row says "context unknown".** Nothing measures a
+  subagent's context; the row could leave it out rather than admit it.