chore(ci): upload only the desktop release files - #56071

Stacked on #56070 (cli-target-jobs) ("chore(ci): build each CLI target in its own job and sign macOS and Windows in parallel"), which is stacked on #55987 (release-runner-moves). Only the last commit belongs to this PR.

Summary

Each build-electron leg uploads all of packages/desktop/dist/* (unpacked app and builder debug files included) at deflate level 6: 769 files, ~1.3 GB and 64–105 s on macOS. publish uses only the top-level installers matched by packages/desktop/scripts/publish.ts's glob, plus the two Windows .exe for WinGet.

This PR changes only that upload step:

• path: one pattern per extension in that glob (@actions/glob can't expand braces), with a comment pointing at publish.ts.
• compression-level: 0: the installers are already compressed.
• if-no-files-found: error: a leg matching nothing fails at upload, not in publish.

The latest-yml-<target> upload is unchanged.

Expected effect

All numbers are estimates from dev releases 38536124977 (2.0.29) and 38785024495 (2.0.30).

• Projection: shipped bytes at the measured upload rate, plus fixed overhead.
• After chore(ci): build macOS x64 and Windows arm64 desktop apps on faster runners #55987, macOS x64 should match arm64 (~35–40 s) and Windows arm64 should match x64 (~13–18 s).
• publish downloads 3.42 GB in 20 files instead of 5.66 GB in ~1,916 files (today 29.0 s and 75.6 s; est. ~18 s and ~45 s).
• Critical path: about 30–50 s per release. After chore(ci): build macOS x64 and Windows arm64 desktop apps on faster runners #55987 linux-arm64 is slowest by ~4–5 min, so a release gains its ~21 s plus 10–30 s in publish. Off the critical path: ~2–2.5 runner-minutes and ~2.2 GB less artifact storage per release.
• Dev pushes without a release skip build-electron and gain nothing.

Evidence

• Same files. 2.0.29 and 2.0.30 each shipped the same 20 opencode-desktop-* files; each matches a new pattern and each pattern matches one.
• Same root, same selection. Running the pinned upload-artifact (ea165f8d) search code offline on fake dist trees picked exactly 5/2/3 files with root packages/desktop/dist, and failed with "No files were found" when no installer existed. publish.ts's glob returns the same list for old and new inputs.
• No other readers. Only publish downloads these artifacts.
• Level 0 round-trips through download-artifact v4.3.0: zips, DMGs and .tar.gz came back byte-identical. Only an entry starting with PK\x07\x08 fails; no shipped format does.
• Checks: actionlint, YAML parse and Prettier are clean.

Things to know

• Keep the list in step with publish.ts. New risk: a change to its glob (or beta's upload.ts glob) must update this list, or that format silently stops shipping.
• if-no-files-found: error only catches a leg with no matches. A single missing extension is caught as today: publish.ts throws for files listed in latest*.yml (12 of 20). The other 8 (.app.tar.gz and blockmaps) are unchecked, before and after this PR. A WinGet failure is only a warning.
• Artifacts no longer hold the unpacked app or builder debug files. Use the installer to inspect the app.
• Failures stop the release before anything ships, whether the upload matches nothing or extraction fails in publish.
• Next merge of dev into beta (checked against origin/beta bd874f4): this hunk merges cleanly and keeps beta's if: github.ref_name != 'beta'. The only conflicts are the 3 publish.yml hunks and the build.ts hunk already in cli-target-jobs. Beta skips this step.
• Possible follow-up: drop the macOS .app.tar.gz on dev, as beta does (about a third of each macOS upload). It changes what ships to R2, so it needs its own PR.

Verification

publish.yml can't run on this PR. On the first dev release dispatch:

• Each opencode-desktop-* upload: "there will be 5 files uploaded" on macOS, 2 on Windows, 3 on Linux; no "least common ancestor" line; size ~780/820 MB macOS, ~230 MB Windows, ~670/690 MB Linux; step time ~25–30 s on macOS and linux-arm64.
• publish: the download reports 6 artifacts in roughly 20–45 s; the desktop dry-run upload: and upload: lines list the same 20 names as 2.0.29/2.0.30; WinGet prepares Anomaly.OpenCode.Desktop.
• Rollback: revert this commit.