Problem

opencode loads instruction files two ways:

1. Eager, session-start: systemPaths resolves AGENTS.md/CLAUDE.md plus config.instructions globs once, up front, into the system prompt.
2. Proximity, on-read: when a file is read, Instruction.find walks up from that file's directory and loads the nearest instruction file — directory-scoped context, pulled in only when you're actually working in that subtree.

The proximity loader only checks a hardcoded list (packages/opencode/src/session/instruction.ts):

const files = (disableClaudeCodePrompt: boolean) => [
  "AGENTS.md",
  ...(disableClaudeCodePrompt ? [] : ["CLAUDE.md"]),
  "CONTEXT.md", // deprecated
]

config.instructions doesn't feed this path — so a custom-named file can't be loaded on proximity. A config.instructions glob would load it eagerly into every session, defeating the point.

Use case

We run dedicated review agents and want directory-scoped review instructions — what to review for, and importantly what not to flag — colocated with the code they apply to.

Today we can add a line in AGENTS.md pointing the agent at a separate review file, but that's non-deterministic: the agent has to decide to read it, it costs a tool call, and it can be skipped. We'd rather the review instructions load deterministically via the same proximity mechanism — guaranteed in context whenever the agent touches that subtree — under their own filename rather than overloading AGENTS.md.

Request

Let the proximity loader (Instruction.find / instructionFiles) honor a configurable list of instruction filenames — e.g. a config key like localInstructionFilenames: ["AGENTS.md", "REVIEW.md"] that extends the hardcoded list.

Happy to send a PR if the team's open to it — the change looks contained to instruction.ts plus the config schema.