Stage 1 of the terminal config/copy-mode arc. The terminal had no
configuration surface at all: the command hardcoded $SHELL, scrollback
was a per-open argument only, and the escape chord was a literal in
Rust. No protocol change.
Profiles are a raw Lua table, pmacs.terminal.profiles, not a registry
setting: ConfigValue is four scalars with no table kind, so profiles
join pmacs.lsp.config and pmacs.pair.sets until table-valued settings
exist. The registry gains three scalars whose defaults reproduce the
previous behavior exactly.
Field resolution is explicit open argument, then profile field, then
scalar setting, then $SHELL. env MERGES, with explicit entries
overriding the profile's, because first-wins there would silently drop
half a user's environment. An explicitly named profile that does not
exist is an error even when terminal.default-profile is valid, so a typo
cannot silently fall back.
The two open-time settings resolve through the GLOBAL chain, because
they are read before the identity buffer exists and no caller could have
pinned a local override on a buffer that does not yet exist. Only
terminal.escape-key resolves per buffer, which makes a per-terminal
escape a supported feature.
The escape key is parsed at most once per (terminal, config epoch), and
the cache lives on TerminalSession so its lifetime is the terminal's,
with no purge hook to forget. The epoch alone is not a sufficient key:
it does not advance when focus moves between two terminals with
different buffer-local values, so an epoch-only cache serves one
terminal's chord to the other. An unparseable value falls back to C-c
and reports once per terminal per effective invalid value through the
status line, because a terminal with no escape chord cannot be escaped
to fix the setting that broke it.
Repeating the escape now sends THAT chord to the child through the
ordinary key encoder, rather than a hardcoded ETX. With an escape of
C-x, the previous code sent Ctrl-C and made literal Ctrl-X unreachable.
C-c t opens a terminal. COHERENCE Priority 1 names a terminal
keybinding, and section 2 step 8 grades the terminal works-but-
undiscoverable; C-c is already a live global prefix, so this is a new
leaf rather than a shadow. It is unreachable from inside a terminal,
where C-c is the escape.
Acceptance is tests/terminal_config_acceptance.rs, deliberately NOT
crdt-gated so CI actually runs it. Four bites, each against a different
plausible wrong implementation: a hardcoded ETX fails acc6/9; an
epoch-only cache key fails acc7; a single last-entry cache fails acc8's
parse count; removing the invalid-value fallback fails acc10.
Two test-instrument notes worth keeping. cat -v is the echo probe
because the screen rejects C0 controls before they reach cells, so a raw
echoed Ctrl-X would be invisible. And the probe counts occurrences
rather than testing presence, because a single-character probe collides
with the child's own banner text.