core: a read-only task board draws no write and says nothing in place about why - #2275

… change (ThinkFlowLab#2265)

Fixes ThinkFlowLab#2247

Owner: Dev2
Reviewer: Reviewer
Claim-Id: ae99f17f04c0438ca64d71ddcfa6f1e9
Branch: dev/2-readonly-banner-reload
Base: 55503e1
Tree: 1795cfb
Verified commit: 4cf69b2
Pushed head: 4cf69b2

**Scope** — the read-only sidebar banner (wide and rail forms) carries a
`Reload` control outside the live region, and the client can ask for a
fresh state answer that is applied even when the revision is unchanged,
so a window that has become writable picks the change up without a page
reload.

Re-tipped onto live main `55503e16b359` (after `ThinkFlowLab#2277`, `ThinkFlowLab#2290` and
`ThinkFlowLab#2275`); `core/client.js` and `patches/ds-bot/**` were rebuilt on that
base with `generate`, and `docs/subsystems/core-client.md` merged with
`ThinkFlowLab#2275`'s kanban line intact — the file is this base plus exactly the
`ThinkFlowLab#2247` bullet. The large generated diff is the usual `generate`
re-alignment of the client bundle (the same shape `ThinkFlowLab#2277` and `ThinkFlowLab#2275`
have); `core/client.js` against this base carries only the `ThinkFlowLab#2247`
hunks.

**Files** (13, +5996/−4469)
- `core/src/client/sidebar.js` — the button in both banner forms
- `core/src/client/sources.js`, `core/src/client/index.js` — the fresh
request and its in-flight guard
- `core/test/client-reload-state.test.js`,
`core/test/sidebar-readonly-reload.test.js` — the new cases
- `docs/subsystems/core-client.md`,
`changelog.d/2247-readonly-banner-reload.fixed.md`
- `core/client.js`, `patches/ds-bot/**` — the generated bundle and
mirrors

**Readings at `4cf69b209` (committed, clean tree)**
- `TZ=UTC ARCH_DOCS_BASE=55503e16b359f034d71328f920aae6bbf674e0d1 npm
run verify` — exit 0, 8 suites, **4656 tests / 4656 pass / 0 fail**,
`arch-docs: OK (13 changed file(s))`.
- `node core/scripts/build-client.mjs --check` — exit 0.
- `node scripts/ds-bot-patches.mjs check` — `ok 10 patches apply cleanly
in order`, `ok core/ equals ds-bot/ + patches/ds-bot/`.
- `node scripts/ds-bot-patches.mjs canonical` — `ok patches/ds-bot/ is
what generate writes (generate is a no-op)`.
- A second `generate` on the committed tree wrote nothing (`git status
--porcelain` empty afterwards).
- Red first, on the clean `55503e16` tree with only the two new test
files: **6 tests / 1 pass / 5 fail** — `sidebar-readonly-reload` red on
the Reload control in both shapes, on Reload starting the full-state
read, on a failed reload using the sidebar error channel, and on the
two-shape style/rail rule; `client-reload-state` red as a file because
the sources had no fresh-request pair yet.
- Conflict markers: `git grep -nE '^(<{7}|={7}|>{7})' -- docs core
patches changelog.d` answers no line (exit 1).

**Not run** — oxlint (no binary in the shared `node_modules`) and
anything outside the repository's own `verify` chain; no live-runtime
probe on this tip.

## Checkpoint

<!-- flybot:checkpoint -->
```json
{
  "pr": 2265,
  "claim": "Dev2",
  "issue": 2247,
  "summary": "The read-only sidebar banner now carries a Reload button in both the wide and the rail shape. It sits beside the status line, not inside the role=status region, so the live region stays text. Pressing it runs the client's new reloadTeam action, which asks the host for a whole team read (no since) so an unchanged revision still re-reads readOnly, and the poll stands back while a reload is in flight. Two new test files cover the control in both shapes, the fresh request, the stale-answer rule and the sidebar error channel.",
  "files": ["core/src/client/sidebar.js", "core/src/client/sources.js", "core/src/client/index.js", "core/test/sidebar-readonly-reload.test.js", "core/test/client-reload-state.test.js", "docs/subsystems/core-client.md", "changelog.d/2247-readonly-banner-reload.fixed.md"],
  "checks": { "ran": "node --import ./test/harness-resolve.mjs --test test/sidebar-readonly-reload.test.js test/client-reload-state.test.js; node core/scripts/build-client.mjs --check; node scripts/ds-bot-patches.mjs check", "result": "green", "at": "4cf69b209b4980f9efdfc85998c08a11672cf972" },
  "next": "none — ready for review"
}
```
<!-- /flybot:checkpoint -->

Co-authored-by: Dev-2 <dev2@flybot.local>