docs: rename per-state advance → advanced_by

`.advance` read like a command (it clashes with the `/advance` operation); `advanced_by`
is the noun form and parallels `turn_on_enter`. The `/advance` core op keeps its name.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: tildesrc

docs/ARCHITECTURE.md

@@ -169,7 +169,7 @@ registration. Sketch of the ABC's two faces:
 
 - **Declarative members** (data the control plane reads):
   - `states` (nested `State` classes) and their `transitions` (class refs or label strings);
-  - per-state `turn_on_enter` (who holds the turn on entry) and `advance` (who transitions
+  - per-state `turn_on_enter` (who holds the turn on entry) and `advanced_by` (who transitions
     out: `USER` — the default — / `AGENT` once satisfied);
   - `responsibilities(state)` → the agent's obligations for that state (each resolves to a
     `status`: `PENDING` → `MET`/`FAILED`, a `FAILED` one needs a comment);
@@ -199,7 +199,7 @@ active workflow*, not a fixed global list.
   creds volume (references, **never secret values**).
 - **Task** — stable internal **id** (generated at creation), `repo_id`, `workflow`, current
   `state`, **`turn`** (`agent`/`user`), git refs (branch/worktree), optional
-  forge refs (PR), and an **optional `slug`** (see §8.3). (Per-state `turn_on_enter`/`advance`
+  forge refs (PR), and an **optional `slug`** (see §8.3). (Per-state `turn_on_enter`/`advanced_by`
   live on the `State` classes, not the task.)
 - **History** — append-only transition log per task. Each entry: timestamp, from/to state,
   via, and the **responsibilities resolved that turn** (each with its `status` and, if

docs/BACKLOG.md

@@ -19,7 +19,7 @@ in the ADRs; this file is for the smaller stuff that doesn't have a home there y
   Pin/upgrade once the ecosystem settles. _(Slice 1, P3)_
 - [ ] **CI doesn't type-check `tests/`** — `mypy -p panopticon` covers the package only.
   Consider adding `mypy tests` (needs path/namespace config). _(Slice 1, P3)_
-- [ ] **`advance` is declared but not engine-enforced** — a state's `advance`
+- [ ] **`advanced_by` is declared but not engine-enforced** — a state's `advanced_by`
   (`USER`/`AGENT`) is queryable metadata; the engine doesn't yet use it to decide who
   may trigger a transition, nor is there a per-*transition* auto-advance flag. Wire it when
   the agent runtime needs it (around the parity workflow, Slice 4). _(Slice 1, P2)_

docs/decisions/0004-workflow-abstraction.md

@@ -62,7 +62,7 @@ Within the class, the two kinds of responsibility are expressed differently:
   - the **state set and legal transitions** (the state machine);
   - per-state **`turn_on_enter`** (who holds the turn on entry) — the agnostic turn-tracking
     starts from it;
-  - per-state **`advance`** — who transitions out: `USER` (the default — e.g. approving a
+  - per-state **`advanced_by`** — who transitions out: `USER` (the default — e.g. approving a
     plan) or `AGENT` (the agent does so once satisfied);
   - the **responsibilities** per state — the agent's obligations to fulfil before handing
     the turn back. Each resolves to a **status** (`PENDING` → `MET`/`FAILED`; a `FAILED`