feat(seats): the env file's settings count, and a machine's own seats file

ApiConfig and PoolConfig read the seat order, the budgets and the
concurrency from the process environment alone, so a `.env` that said
REVIEW_GATES_SEAT_ORDER=oauth-first ordered nothing: the Python driver
reads those lines from the file under the process environment
(config_env, 2026-10-17: a setting lives beside the seats it orders).
SeatPool::SettingsOf does the same - the file's placement settings
under the process environment, in a map handed to the placement readers
alone (ApiConfig, PoolConfig, Seats::ConfigFromEnv) - and leaves the
process environment untouched, so no other reader sees a line of the
file: a path's or a binary's line reaches nothing, and two drivers
reading one .env keep one board and one ledger. The placement settings
are one list, SeatPool::PlacementSettings - the fifteen names those
readers read - for the map, the run's log and what makes a working
directory's .env a seats file; a REVIEW_GATES_* line of any other name
stays out of the map and is named, by the run's log and on `seats`'s
stderr. One dotenv grammar serves the tokens and the settings
(Seats::DotenvLines).

`run` and `seats` resolve the file from their own --env-file
(SeatPool::ResolveSeatsFile): the --env-file, else $SEATS_ENV_FILE, else
the working directory's .env - the operator's, as the Python driver and
`seats` read it, not the repository under review's - when it is a file
holding a seat or a placement setting, each with a value, or one that
cannot be read as UTF-8 text (its error is then the command's) - a
readable application .env, its Vite or Supabase lines, one of blank
placeholder lines or one that is no file is passed over, and the run
says so - else the machine's own
$XDG_CONFIG_HOME/crafter-review/env, else ~/.config/crafter-review/env:
one file for every repository on a machine, a repository's seats .env
winning over it. Each file is read once and the settings and the tokens
are taken from that read (SeatsFile::Text), so a file that can be read
only once - a pipe, `--env-file <(gpg -d seats.env.gpg)`, a FIFO - gives
its settings and its seats alike, and a failed read raises its own error
where the tokens are laid over the environment: SeatPool::WithFileTokens,
for `run` and `seats` alike, and LoadSeats takes the merged environment
and no longer reads a file by path. An empty `seats --env-file` means no file
now, as it did for `run`, and the `seats` report names the side that
runs first (it said "api seats run first" whatever the order).

Runs, Commands and KernelModes, the tests that run `run` and `seats`,
point XDG_CONFIG_HOME, and HOST_XDG_CONFIG_HOME for the Flatpak, at a
path of their own that nothing creates, so a global file stays out of
them; the grammar, the settings and their precedence, the lookup and the
one read have their tests, a run with `--env` (a prefix) and with a
repeated --env-file, and a `seats` with `--env`, take tokens and
settings from the one file, an application's .env and a venv are passed
over, a FIFO is read once, no line of the file reaches `stop`, every
listed placement setting moves a reader, another REVIEW_GATES_* line is
named and a .env of blank lines passed over, and the
README, the environment table and the procedure say the new rule.

README.md

@@ -28,7 +28,7 @@ alias crafter-review='flatpak run net.catcrafts.CrafterReview'
 What the machine provides:
 
 - **The Claude Code CLI.** It is proprietary and not bundled. crafter-review looks for it in this order: `CLAUDE_BIN` or `REVIEW_GATES_CLAUDE_BIN`, the PATH, the editor extensions' bundled binary (newest first), then `~/.claude/local` and `~/.local/bin`. It runs inside the sandbox, so every pass is measured and every pass's process tree can be killed.
-- **Seats.** The lens processes run on the seats in the repository's `.env` (`CLAUDE_CODE_OAUTH_TOKEN1..6`, `ANTHROPIC_API_KEY1..6`), else this machine's own login. `crafter-review seats` probes and reports them. It never prints a token. An account whose 5-hour limit Anthropic has removed shows `no limit` in that column and is placed by its weekly window. Every account takes at most 128 passes at once, every driver's counted, and there is no machine-wide cap beyond that and free memory (`run --concurrency N` sets one).
+- **Seats.** The lens processes run on the seats of a dotenv file (`CLAUDE_CODE_OAUTH_TOKEN1..6`, `ANTHROPIC_API_KEY1..6`): `--env-file`, else `$SEATS_ENV_FILE`, else the working directory's `.env` if it is a file holding a seat or a placement setting, or one that cannot be read as UTF-8 text (its read error then stops `run` and `seats`) - a readable application `.env` is passed over, and the run says so - else the machine's own `~/.config/crafter-review/env` (`$XDG_CONFIG_HOME/crafter-review/env`: one file for every repository, a repository's seats `.env` winning over it). Its seat lines go over the process environment's; with no seat in either, this machine's own login. The placement settings among its lines - the seat order, the budgets, the concurrency, the utilisation ceilings - are read with it, under the process environment; any other `REVIEW_GATES_*` line (a path, a binary) is not, and `run` and `seats` name it. `crafter-review seats` probes and reports them. It never prints a token. An account whose 5-hour limit Anthropic has removed shows `no limit` in that column and is placed by its weekly window. Every account takes at most 128 passes at once, every driver's counted, and there is no machine-wide cap beyond that and free memory (`run --concurrency N` sets one).
 - **Chromium, for a lens with the browser.** Run `crafter-review browser install` once. It installs the Chromium build the pinned `@playwright/mcp@0.0.83` drives into `~/.cache/ms-playwright`, where the MCP server looks. It runs Playwright's own installer, which also removes the browser builds no installed Playwright on the machine refers to.
 - **A local Supabase stack, for a lens with the database** (`supabase start`, or the repository's own bring-up). The `sql` helper speaks the Postgres protocol itself: no `psql` and no driver to install. Every call is one transaction, rolled back.
 - **gpg, if your commits are signed.** `freeze` reads each commit's signature through gnupg's keyboxd socket, which is all the sandbox is given. The agent, which signs, stays out of reach.
@@ -88,7 +88,7 @@ The dump with every finding, note and coverage entry is `gate-state/commits-<has
 
 ### Reviewing another repository
 
-A directory can review repositories other than itself: a workbench whose config, `.env` and records serve several. From it, `crafter-review freeze --repo <path> --out <dir> --worktree`, then the printed run line. The run reads the repository under review from the artifact's `freeze.json`: the prompt names it, the calibration is kept under it, and `--trees` defaults to the recorded worktree. The config, the env file and the slots are the working directory's, the lenses run in it, and `--context-paths` are relative to it.
+A directory can review repositories other than itself: a workbench whose config, `.env` and records serve several. From it, `crafter-review freeze --repo <path> --out <dir> --worktree`, then the printed run line. The run reads the repository under review from the artifact's `freeze.json`: the prompt names it, the calibration is kept under it, and `--trees` defaults to the recorded worktree. The config and the slots are the working directory's, the seats file is looked up from it (Seats, above), the lenses run in it, and `--context-paths` are relative to it.
 
 ### The kernel modes: a patch series, a mailing-list reply