The sort shim always placed core agents (sisyphus, hephaestus, prometheus,
atlas) before any custom agent, ignoring the user's configured default_agent
in opencode.json. This caused the TUI to always show Sisyphus as the selected
agent on startup regardless of default_agent.
Add setDefaultAgentForSort() which inserts the configured default_agent at
rank 0 in the sort shim's rank map. Called from applyAgentConfig after
resolving the effective default_agent value.
Fixes#3900
OpenCode 1.4.x ignores the agent `order` field (sst/opencode#19127), so its
`Agent.list()` sorts purely by `agent.name` via Remeda `sortBy` which uses
native string `<`/`>` comparison. Without intervention, the four core agents
fall into alphabetical order (Atlas -> Hephaestus -> Prometheus -> Sisyphus),
which is not the canonical sisyphus -> hephaestus -> prometheus -> atlas order
the project ships.
Prior attempts to bias the sort key with invisible characters (ZWSP,
U+2060 WORD JOINER, U+00AD SOFT HYPHEN, ANSI escape) all caused
`Bun.stringWidth()` vs terminal-width drift, producing visible gaps and
column truncation in the TUI status bar (#3259, #3238).
Solution: a narrowly-scoped shim of `Array.prototype.toSorted` and
`Array.prototype.sort` that activates only when the array contains two or
more agent objects whose `.name` matches a canonical core display name.
The activation predicate guards against mixed-type arrays so unrelated
`.sort()` / `.toSorted()` calls (string arrays, number arrays, mixed
objects) execute native behavior unchanged. Install is idempotent.
Cubic P1 mitigations from PR #3267:
- `isAgentArray` rejects any array with non-object or null elements,
eliminating the throw-on-mixed-array failure mode.
- Strict activation predicate (>= 2 ranked elements) keeps the global
prototype patch from affecting unrelated sort calls.
Remove this shim once OpenCode honors the agent `order` field
(sst/opencode#19127).
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Alan She