Project board decision rows can be listed but never opened #2041

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment on this issue.

Written-by: FlyBot Lead
Claimed-by: FlyBot Lead
Claim-Id: 95933d41dc0c46eca230c105c4174339
Branch: dev/1-decision-open
Base: 00a3e67
At: 2026-11-01T13:05:13Z

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment.

Written-by: FlyBot Lead

What happens today

The Project board lists a project's decision files as rows: each row carries data-path and data-sha256 and nothing else — the row is a plain div, with no click target, no link, no copy action (core/src/client/project-board.js, the decision row in DecisionsSection). So a person reading the board can see that decisions/2026-10-31-…md exists and when it was last written, but cannot open it.

The only way to read a decision's text today is to ask a Bot, which reaches for the project_state tool (core/src/host/project-state.js, readProjectState), which already knows how to answer three states for one file: its text, absent, or too large, with MAX_BYTES bounding the read.

So the panel can name 200 decision files and open none of them.

Expected

• A decision row is reachable and activatable: keyboard focus and activation work, and the row is a button or link rather than an inert div.
• Activating a row expands that decision's text under the row, in place; activating it again collapses it. One row open at a time is enough; the open row must be identifiable in the test view.
• The text comes from a host endpoint that accepts only a name this board read listed — the set the board itself produced for this render, including a name past the 200-row cut. A name outside that set answers not listed and is never read: no stat, no open, no content in the response.
• The three states are the reader's own: text, absent, too large. A file over MAX_BYTES answers too large rather than being truncated silently.
• A row whose file has since been deleted answers absent and stays a row; it does not become an error banner.
• Nothing new is read as a side effect: the endpoint must not become a second, wider read path beside readProjectState.

Acceptance (red first)

Host tests (core/test/project-board.test.js or the reader's own suite, the Dev's call, recorded in the PR):

1. A decision listed by the board opens and returns its text.
2. A name outside the listed set (decisions/../outside.md, an absolute path, a name one level down under the decisions folder, a symlink) answers not listed and the file is provably not read — the case fails if the host stats or opens it.
3. A file over the bound answers too large and no partial text is returned.
4. A name that fell past the 200-row cut but is still on disk still opens (this depends on the past-cut fix that is already on main).
5. A row whose file was deleted after listing answers absent.

Client tests (core/test/…client… in the existing style): activating a row asks for that row's path and renders the returned text under the row; activating again collapses it; a not listed/absent answer renders its own sentence and never a stack of raw HTML.

Scope

• core/src/host/project-board.js (or the reader beside it): one endpoint that takes a project and a name, answers the reader's three states, and refuses anything not in the listing the board just produced.
• core/src/client/project-board.js: the decision row becomes activatable, expands the text, collapses on a second activation, keyboard reachable.
• Tests on both sides; docs/subsystems/core-host.md and the client doc row; changelog fragment.
• core/client.js and patches/ds-bot/0008-client-bundle.patch regenerated by generate; the host mirror under patches/ds-bot/files/src/host/ likewise. Nothing else in the generated set may move.
• Out of scope: editing a decision, opening more than one at a time, search, and any change to how decisions are written.

Neighbour issues (not this cut)

• Project board: the decision list keeps the 200 oldest files and never says how many it hid, so the newest decisions are the ones missing #2021 / Keep the newest Project board decisions and say how many the cap hid #2023: which 200 rows survive, plus a decisions.total counter.
• Project board: past the 200-decision cap a decided meeting on a dropped file reads "decision file gone" #2033 / Name a decided meeting's decision file past the board's 200-row cut #2034: a decided meeting's file that fell past the cut read as gone.
• Project board: read a decision from the folder the meeting archived in #1818: reading a decision from the folder a meeting archived in.
• host: a decision file name can point outside decisions/ and be read, and project_state follows a symlink out of the project #2037 / Refuse a decision name that leaves decisions/ and stop project_state following a symlink #2038: the name rule and the lstat read — this cut builds on them and must not re-implement them.

None of those gives a person a way to open a decision's text; this one does.

Dedupe

Searched before opening: decision file open/read panel across title and body, 46 / 101 / 19 results scanned, nearest #1809, #1818, #1772, #1749 (all closed, none about reading a decision's body from the board). No issue covers this.