docs: agent_model and factory.md in capy-install, model-policy, troubleshooting and capy/README

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

capy/README.md

@@ -211,7 +211,7 @@ did it go on by default.
 
 - [docs/recommended-harness.md](../docs/recommended-harness.md): set it up, day 0 to the first merged train.
 - [docs/captain.md](../docs/captain.md): the controller's reference (READY contract, trains, approvals, digest, flaky pass).
-- [capy/skill/gstack/](skill/gstack/): the Capy skill every thread loads, and its [captain.md](skill/gstack/captain.md) for lanes.
+- [capy/skill/gstack/](skill/gstack/): the Capy skill every thread loads, its [factory.md](skill/gstack/factory.md) one-page summary of how crews work, and its [captain.md](skill/gstack/captain.md) for lanes.
 - [docs/why-gstack.md](../docs/why-gstack.md): the longer story behind gstack itself.
 
 [^1]: Windows are UTC, [2026-10-01, 2026-10-15) before and

docs/capy-install.md

@@ -423,6 +423,11 @@ GSTACK_LAUNCH_FILE: <verdict file without .json>.env
 
 `GSTACK_LAUNCH_FILE` names the same assignments as a sourceable script (mode
 0600, beside the verdict under the state root; the PATH prepend is idempotent).
+When the session starts from the Drive skill (a bootstrapper outside the
+checkout), the file also exports `GSTACK_PREFERENCES_FILE`, the path of
+`preferences.yaml` beside that skill's SKILL.md, which the `GSTACK_LAUNCH` line
+leaves out; `gstack-models resolve --role agent` reads it
+([your model preference](model-policy.md#your-model-preference)).
 The file is part of the ok verdict: a passing run that cannot write it exits 1
 with `gstack: fail launch-file — could not write the launch file <path>; fix:
 make <dir> writable, or set GSTACK_STATE_ROOT to a writable directory

docs/model-policy.md

@@ -256,6 +256,9 @@ an environment pin. See [selection recovery](troubleshooting.md#model-policy-sel
 `gstack-models` with no arguments is `list`. Both `list` and `resolve` accept
 `--json`. Plan-review resolution requires `--provider anthropic|openai`;
 implementation resolution can omit the provider to return both recommendations.
+Agent resolution (`--role agent`) takes no `--provider`; its JSON carries an
+`agent` object instead of `selections`, and `list --json` adds the same
+top-level `agent` key.
 
 ```bash
 "$GSTACK_ROOT/bin/gstack-models" resolve --role plan-review --provider anthropic --json

docs/troubleshooting.md

@@ -37,7 +37,7 @@ no paid call: the Codex rows report the cached model check and its age, and
 
 ## Model policy
 
-The [model-policy guide](model-policy.md) explains the two tiers, all six
+The [model-policy guide](model-policy.md) explains the two tiers, all seven
 settings, precedence and the read-only inspection command. A resolved selection
 is not proof that the requested provider or model can run.