docs(m1): record Cowork probe results and degradation branch

Plan Step 1. Builds the probe vehicle and the checklist; does NOT answer it.

The four questions all require the operator in a live Cowork session on this
Mac, and that is a fact about the measurement rather than a caveat: measured
2026-09-04, the session mode is not readable from disk (cowork_settings.json
carries only extraKnownMarketplaces; the desktop config carries
coworkNetworkMode and a trusted-folder list, neither states where a session
runs), and the other three each need a plugin installed in a live session.

The step's Verify is therefore RED on purpose and stays red until the operator
answers:
  test "$(grep -cE '...' docs/cowork-probe.md)" = 4   -> exit 1 (0 of 4 matched)
Validated in both directions: a fully answered copy exits 0, a copy with three
of four answered exits 1. The gate can pass, so its failure means something.

Probe vehicle: jobbsok-probe, exactly four files under
tests/fixtures/cowork-probe/ -- manifest, skills/probe-versjon/SKILL.md,
.mcp.json declaring the stdio server probe-tools, and probe_tools.py (standard
library only). Smoke-tested from Claude Code: initialize handshake completes,
tools/list returns probe_ping, tools/call returns an interpreter version, an
unknown tool name is rejected. What is NOT verified is whether Cowork ever
starts it -- that is the question.

Archive is built from an explicit four-file include list, never zip -r over the
repo root; verified to contain no .git, STATE.md, .venv or .claude/ entry.

The degradation branch for each possible nei is written down now, before any
answer is known, so it is not decided under pressure later.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docs/cowork-probe.md

@@ -0,0 +1,123 @@
+# Cowork probe
+
+Plan Step 1 (M1). An empirical record of what this operator's Cowork
+installation actually does, measured before any code depends on it.
+
+Operator decision 7 — Python as a CLI plus a host-side stdio MCP server — is
+void if host-side servers never appear in a Cowork session. That is not
+knowable from Claude Code, so it is measured here first, and the milestone that
+depends on it carries a written degradation branch either way.
+
+**Status: unanswered.** All four questions require the operator sitting in a
+Cowork session on this Mac. The executor session built the probe vehicle and
+this checklist; it did not and could not answer them. The verify command for
+this step is written so an unanswered checklist *fails*:
+
+```bash
+test "$(grep -cE '^- (Sesjonsmodus|Host-MCP|python3|CLAUDE_PLUGIN_ROOT): +(lokal VM|sky|ja|nei)\b' docs/cowork-probe.md)" = 4
+```
+
+A bullet still reading `ubesvart` does not match, the count drops below four,
+and the command exits non-zero. That is the intended behaviour until the
+operator has run the probe.
+
+## Results
+
+Overwrite `ubesvart` with one of the allowed answers, and put the date of the
+measurement in the Measured column. A `nei` is a result, not a failure — it
+selects the degradation branch below.
+
+- Sesjonsmodus: ubesvart
+- Host-MCP: ubesvart
+- python3: ubesvart
+- CLAUDE_PLUGIN_ROOT: ubesvart
+
+| Bullet | What the operator does in Cowork | Allowed answer | Measured |
+|---|---|---|---|
+| `- Sesjonsmodus:` | Open a Cowork session and read whether it is a local VM or cloud | `lokal VM` or `sky` | |
+| `- Host-MCP:` | Upload `jobbsok-probe.plugin` via Customize -> Plugins; does `probe-tools` appear as a connector, and does `probe_ping` return? | `ja` or `nei` | |
+| `- python3:` | Run the `probe-versjon` skill; does it succeed in invoking `python3`, and which version does it report? | `ja` or `nei`, followed by the reported version | |
+| `- CLAUDE_PLUGIN_ROOT:` | Run `probe-versjon`; does it print a resolved absolute path, or the literal variable name? | `ja` or `nei` | |
+
+### What is already known, and what is not
+
+Measured 2026-09-04 from Claude Code, before the probe was built:
+
+- Cowork is installed and available on this Intel Mac.
+- The **session mode is not readable from disk.** `cowork_settings.json` carries
+  only `extraKnownMarketplaces`; the desktop config carries `coworkNetworkMode`
+  and a trusted-folder list, and neither states where a session runs. So
+  `- Sesjonsmodus:` cannot be answered by reading files — it has to be read off
+  a live session.
+- The other three each require a plugin installed in a live Cowork session.
+  Nothing about them is decidable from Claude Code.
+
+## The probe vehicle
+
+`jobbsok-probe` — a throwaway test plugin, deliberately **not** the `jobbsok`
+plugin itself. `jobbsok`'s own `.mcp.json` (Step 12) and packaging script
+(Step 13) land eleven steps later, and this probe must not wait for them.
+
+It holds exactly four files, under `tests/fixtures/cowork-probe/`:
+
+| File | What it is for |
+|---|---|
+| `.claude-plugin/plugin.json` | Manifest. Name `jobbsok-probe`, version `0.0.1`. The version is what `probe-versjon` echoes, so a mismatch reveals a cached build. |
+| `skills/probe-versjon/SKILL.md` | A skill that reports the manifest version, the resolved `${CLAUDE_PLUGIN_ROOT}`, and whether it can invoke `python3`. Answers three of the four questions. |
+| `.mcp.json` | Declares one stdio server, `probe-tools`. Its appearance in the session is the whole `- Host-MCP:` question. |
+| `probe_tools.py` | Standard-library JSON-RPC server exposing one tool, `probe_ping`, returning the interpreter actually running it. No third-party imports: a server that failed on a missing dependency would answer a different question than the one asked. |
+
+Verified from Claude Code 2026-09-04: the server completes an `initialize`
+handshake, lists `probe_ping`, returns an interpreter version on
+`tools/call`, and rejects an unknown tool name. What is unverified is whether
+Cowork ever starts it.
+
+### Building the archive
+
+Run from the repository root. The file list is explicit, and that is the point:
+
+```bash
+cd tests/fixtures/cowork-probe && \
+  zip -X /tmp/jobbsok-probe.plugin \
+    .claude-plugin/plugin.json \
+    .mcp.json \
+    probe_tools.py \
+    skills/probe-versjon/SKILL.md
+```
+
+Never `zip -r` over the repository root. A recursive archive of the repo would
+ship `.git`, `STATE.md`, `.claude/` and the virtualenv into an uploaded plugin.
+The include list above names the four files and can carry nothing else.
+
+Then upload `/tmp/jobbsok-probe.plugin` through Customize -> Plugins, run the
+`probe-versjon` skill, and check whether `probe-tools` appears as a connector.
+
+## Degradation branch
+
+Written now, so the answer does not get decided under pressure later.
+
+**If `- Host-MCP:` is `nei`** — host-side stdio servers do not appear in this
+Cowork installation:
+
+1. Operator decision 7's Cowork half is unavailable. Nothing changes for Claude
+   Code, where the scripts are invoked directly.
+2. Every script-backed skill degrades to reading files that the Claude Code CLI
+   produced. The skills stay useful; they stop being able to compute.
+3. `Verifiser i Cowork` for the affected milestones means "the skills load and
+   read files produced from Claude Code" — not "the connector answers".
+4. The degradation is recorded in `STATE.md`.
+
+This is risk H12's mitigation, and it is why the probe is the first step of the
+build rather than a later check.
+
+**If `- python3:` is `nei`** — a skill cannot invoke `python3` in a Cowork
+session: the same degradation applies, and more broadly, since it removes the
+CLI half too. Escalate to the operator before building further on decision 7.
+
+**If `- CLAUDE_PLUGIN_ROOT:` is `nei`** — the variable does not resolve: every
+intra-plugin path in the plan is affected, not just this milestone's. Escalate;
+do not paper over it with hardcoded paths.
+
+**If `- Sesjonsmodus:` is `sky`** — sessions run in the cloud, and host-side
+servers cannot reach this machine at all. `- Host-MCP:` should then read `nei`,
+and its branch applies. If the two disagree, the disagreement is the finding.