feat(skills): add interactive captain aside sessions

.agents/skills/aside/SKILL.md

@@ -0,0 +1,30 @@
+---
+name: aside
+description: >-
+  Open a dedicated interactive window the captain talks to directly for ad-hoc, multi-turn context-gathering, then hand the outcome back to the main firstmate.
+  Invoke when the captain says /aside, wants a side conversation or scratch space for a topic, or asks to work something out interactively instead of loading it into the main chat.
+user-invocable: true
+metadata:
+  internal: true
+---
+
+# aside
+
+An aside is an interactive scout: a scout-shaped window the captain converses with DIRECTLY to gather context, that concludes back to the main firstmate.
+This is a deliberate captain opt-in that bends hard rule 4 (a crewmate never addresses the captain) for this one session only; every other supervision and safety rule still holds.
+Keep it minimal - this is a chat space, not project work, so no PR and no lavish unless the captain asks.
+
+1. Resolve a short task id (e.g. `aside-<topic>`) and a working directory: the relevant project clone under `projects/` if the aside is about one, otherwise this firstmate repo so the window still gets an isolated scratch worktree.
+2. Scaffold a scout brief: `bin/fm-brief.sh <id> <repo-name> --scout`.
+   Replace `{TASK}` with the aside contract: this is an INTERACTIVE, captain-facing session; talk to the captain directly in this window (a deliberate bend of hard rule 4); gather context on the topic through as many turns as the captain wants; do NOT do project work or open a PR.
+   Replace the scaffold's `Work on your own; do not wait for a human` clause with an explicit override: this session MUST wait for the captain and converse with the captain directly across turns.
+   Replace the scaffold's external-wait-only `paused:` clause with an explicit override: append `paused: awaiting captain` to `state/<id>.status` after every turn that awaits the captain's reply, treating that bounded human-wait as healthy idle.
+   Replace the scout's self-determined completion trigger with an explicit override: the session MUST NOT conclude because it judges the topic settled, complete, or resolved.
+   Only the captain explicitly saying they are done triggers handback: write the outcome to `data/<id>/report.md`, then append `done: <one-line outcome>` to `state/<id>.status`.
+3. Spawn it: `bin/fm-spawn.sh <id> <working-dir> --scout`.
+4. Tell the captain, in plain language, which window to switch to (the `window=` value the spawn printed) to start the conversation.
+   Then resume ordinary supervision; the aside runs on its own and wakes firstmate through its status line.
+5. On the `done:` status, read `data/<id>/report.md`, relay the outcome to the captain, and tear the window down with `bin/fm-teardown.sh <id>`.
+
+Steer the session only if needed with a short `bin/fm-send.sh` line; the captain drives it directly, so firstmate normally stays out of the way until it concludes.
+Reconcile an aside's `paused: awaiting captain` idle as healthy: it is a captain conversation in progress, not a stalled worker, so leave the window alone and recheck on the long paused cadence until it reports `done:`.

docs/documentation-audiences.json

@@ -116,6 +116,10 @@
       "path": ".agents/skills/ahoy/SKILL.md",
       "audience": "agent-runtime"
     },
+    {
+      "path": ".agents/skills/aside/SKILL.md",
+      "audience": "agent-runtime"
+    },
     {
       "path": ".agents/skills/ask-user-authority/SKILL.md",
       "audience": "agent-runtime"

tests/fm-send-popup-settle.test.sh

@@ -37,6 +37,7 @@ set -u
 SEND="$ROOT/bin/fm-send.sh"
 
 TMP_ROOT=$(fm_test_tmproot fm-send-popup-settle)
+POPUP_CASE_INDEX=0
 
 # Same stub shape as fm-send-settle.test.sh: a fake tmux that drives the submit
 # path to a clean "empty" verdict on the first Enter, and a fake sleep that records
@@ -79,7 +80,8 @@ first_settle() {  # <expected> <label> <harness|--explicit> <message> [selector-
   local expected=$1 label=$2 harness=$3 msg=$4
   local selector_form=${5:-legacy}
   local dir fb log home target rc first meta_id
-  dir="$TMP_ROOT/case-$RANDOM"; mkdir -p "$dir/state"
+  POPUP_CASE_INDEX=$((POPUP_CASE_INDEX + 1))
+  dir="$TMP_ROOT/case-$POPUP_CASE_INDEX"; mkdir -p "$dir/state"
   fb=$(make_stubs "$dir"); log="$dir/sleep.log"; home="$dir"
   if [ "$harness" = --explicit ]; then
     target="sess:win"