fix: remove the .mode override; mode selection falls through to inference

.gitignore

@@ -47,10 +47,6 @@ papers/
 # no newcomer-mode defaults). See AGENTS.md and modes/maintainer.md.
 .maintainer
 
-# Interaction-mode override — optional per-clone file containing `teacher` or
-# `assistant`. See AGENTS.md "Modes". `.maintainer` outranks it.
-.mode
-
 # Claude Code agent worktrees — ephemeral, machine-local.
 .claude/worktrees/
 

AGENTS.md

@@ -102,10 +102,12 @@ how it paces the work, not which workflows exist:
   execute with checkpoints — proactive but not silent; state in `wiki/project/`. The dial is
   in [`modes/assistant.md`](./modes/assistant.md) "The autonomy dial".
 
-Select (first match): explicit instruction → `.mode` file → `profile.md` "Interaction mode" →
-else **infer from the opening request** (fall back to **assistant**); `.maintainer` outranks
-`.mode`. State an inferred mode in one line and invite correction; acknowledge an explicit
-one only if it changes behavior. Read `modes/<mode>.md`; depth still follows
+Select (first match): explicit instruction → `profile.md` "Interaction mode" → else **infer
+from the opening request** (fall back to **assistant**); `.maintainer` outranks both. There
+are exactly two mode names — a value that isn't one of them (e.g. `agent`, removed in July
+2026) is **not** a mode: ignore it, say so in one line, and fall through to inference rather
+than improvising. State an inferred mode in one line and invite correction; acknowledge an
+explicit one only if it changes behavior. Read `modes/<mode>.md`; depth still follows
 `skills/_style.md` "Adaptive depth".
 
 ---

README.md

@@ -49,8 +49,8 @@ manage an end-to-end lens modeling project directly on your machine. See
 The assistant works in two modes, and you never have to choose one — it **infers the mode
 from your first message and tells you which it picked** (e.g. *"Mode: teacher — I'll explain
 as we go."*). If it guesses wrong, just say so. To set the mode yourself, start your message
-with it (the examples below do exactly that); to make a choice permanent, drop a `.mode` file
-in the repo containing `teacher` or `assistant`.
+with it (the examples below do exactly that); to make a choice permanent, record it under
+"Interaction mode" in `wiki/project/profile.md`.
 
 - **Teacher** — *learn the workflow.* `Teacher mode: I'm new to PyAutoLens — how do I model this image?`
 - **Assistant** — *do the workflow.* `Assistant mode: set up a project for this dataset and write the first script.`

modes/maintainer.md

@@ -64,7 +64,7 @@ generalise anything pre-emptively; just avoid entangling the two sides.
 **Generic assistant infrastructure** (clones to any domain assistant near-verbatim):
 `AGENTS.md`'s skeleton (session start, safety invariants, three-layer model, mode
 selection, source-of-truth resolution, commit cadence), the Teacher/Assistant mode model
-and `modes/` machinery (`.mode`, `.maintainer` sentinels), the skills framework
+and `modes/` machinery (the `.maintainer` sentinel), the skills framework
 (`_style.md`, `_bootstrap_skill.md`, the README index conventions), the
 `core`/`literature`/`project` wiki split and its read-only/update rules, the science-project
 lifecycle (`start-new-project`, `contribute-upstream`), `sources.yaml` + the source