## Problem
On an Ubuntu 24.04 VM, OpenCode 1.17.18 was installed by curl in
`~/.opencode/bin` and also linked as `~/.local/bin/opencode`. With that
setup, the OpenCode panel offered **no installation**, only the generic
"Select a supported executable or install @opencode/cli on the execution
host" advice.
On macOS/Linux the user npm prefix is `~/.local`, so that link occupies
OpenCode's command name exactly where OpenCode 2 would be installed
beside the older version. npm refuses to link over it, and CodeNomad
never modifies a foreign installation. The plan therefore correctly had
no prefix, but nothing told the user why.
## Fix
`sharedInstallationPlan` reports the obstacle on the foreign
installation, forwarded as `foreignInstallation.blocked`:
| `reason` | `path` | When |
|---|---|---|
| `occupied` | the occupying command | a non-npm command holds
OpenCode's name in the user npm bin directory |
| `unwritable` | the user npm prefix | the prefix, or a recognized npm
installation in it (an `@opencode/cli` launcher, a Windows npm shim or
an `opencode-ai` 1.x installation), cannot be written |
The installation notice then says how to clear it: move or rename that
command, or fix the folder's permissions, then choose **Check status and
updates**. The usual curl layout, on PATH only through
`~/.opencode/bin`, still offers **Install OpenCode 2 for CodeNomad**.
This was verified on the same VM, where the installation then succeeded.
The English messages and their nine translations, the `opencode.md` help
page in all ten locales and `dev-docs/OPENCODE_RUNTIME_SETUP.md`
describe the obstacle.
## Tests
- `legacy-installation.test.ts`: builds the exact VM layout (link in the
user npm bin directory) and checks that the plan never offers a prefix
over the foreign command and reports `occupied`. The ordinary layout
must still offer the prefix, and a read-only prefix must report
`unwritable` (POSIX, non-root).
- `opencode-setup.test.ts`: renders the occupied notice with no install
action.
- A second POSIX regression puts a verified npm OpenCode 1.x
installation in a read-only user prefix and expects `unwritable`, never
`occupied`.
- Results:
- the `opencode-update` unit tests: 51/51 on Windows (1 POSIX-only
skipped); on the Ubuntu VM as uid 1000, 48 passed, 0 failed, 4
Windows-only skipped, including both POSIX cases;
- the `opencode-setup` browser tests: 34/34;
- the server and UI typechecks;
- `npm run test:help`.
AGENTS.md loaded about 33,000 tokens into every agent session, subagent and reviewer, mostly per-feature contracts, and the agent documentation around it had accumulated duplicates, dated logs and history of removed designs. This PR makes AGENTS.md a short set of rules that apply everywhere plus an index of area documents, and leaves AGENTS.md, dev-docs and the repository skills describing only the current state.
Three commits, reviewable separately:
1. **Move (lossless).** Every per-area rule moved verbatim from AGENTS.md into its area document (existing ones, or six new ones: UI_CONVENTIONS, UI_SHELL, COMPOSER, TRANSCRIPT, SETTINGS, PROJECTS). A script split the old file into 208 units, required one destination for each and checked all 199 content units verbatim at their destination. AGENTS.md went from 134,000 to 16,000 characters.
2. **Trim.** A per-area ponytail review removed rules stated two or three times (keeping the more precise copy), dated validation logs, per-version qualification sections below the current minimum, abandoned designs and self-references; seven documents whose surviving rules live elsewhere were deleted. It also fixed statements the code contradicts (locale registration, the Mission play/recovery condition, plugin package updates, cleanup progress UI, timeline index persistence, automation restart/targets, stale pins and minimums).
3. **Current state only.** The new AGENTS.md rule: no history (removed features and their names, former behavior, provenance, dated logs) and no denials; correct a contradicted statement at its source. DEVELOPER_MODE.md is merged into BROWSER_AUTOMATION.md and every Developer Mode mention is gone (including the README and the browser help page in ten locales). Names that only made sense against older designs are renamed with every reference updated, MISSIONS_ENVIRONMENT_ADMISSION is folded into SESSION_ENVIRONMENT, and INDEX lists every document. The server npm README now states the real OpenCode minimum (2.1.2).
AGENTS.md is now about 14,000 characters (roughly 3,500 tokens); AGENTS.md, dev-docs and the vendor README went from about 11,200 lines to under 4,700.
Validation: every relative Markdown link and every cited dev-docs path resolves; no reference to a renamed or deleted document remains; `npm run test:help` passes for all ten locales.
Review: three independent GPT-6.1 Sol (high) reviews by area found binding rules lost in the trim and current-state passes; 25 were restored as present-tense facts or prohibitions and four contradicting statements corrected, each checked against code. A Fable 5.1 gatekeeper review of the whole PR passed; its follow-up routes session recovery from the index, points to dev-docs/INDEX.md and documents the family identity read.
