fix(cli): os doctor tells a broken cloud-connection install from an absent one (#5644)

.changeset/doctor-optional-package-load-boundary.md

@@ -0,0 +1,59 @@
+---
+"@objectstack/cli": patch
+---
+
+fix(cli): `os doctor` no longer treats a broken `@objectstack/cloud-connection` install as "not installed" (#5644)
+
+`readInstalledPackageEntries()` reached the installed-package ledger through a
+dynamic `import('@objectstack/cloud-connection')` whose `catch` meant "the
+optional package is not installed". That is right for one of the two things it
+caught:
+
+- **The specifier does not resolve** — the optional package really is not
+  there. Silence is correct and unchanged: `os doctor` must run to completion in
+  a checkout that never had it.
+- **The package is installed and will not load** — a pruned or unbuilt `dist/`,
+  an interrupted install, an artefact that throws while it evaluates, a
+  transitive dependency missing under it. It threw too, so it was answered with
+  the same silence.
+
+The ADR-0120 D5e unique-scope advisory then saw "no installed packages", found
+nothing to report, and the run printed:
+
+```
+  ✓ Unique scope          No unconfirmed installation-wide uniques for this 'isolated' environment
+```
+
+Measured: with the package present-but-unloadable and a ledger declaring an
+installation-wide `unique`, that line was printed and the finding appeared
+nowhere, `--verbose` included. It is the same false PASS #5412 removed at the
+`readdir` boundary and #5413 at the entry boundary, one boundary further up —
+and `os serve`, loading the same package in the same directory, has always named
+the failure out loud.
+
+The two states are now separated by **resolution**, not by the `import()` having
+thrown (`isModuleNotFoundError()` first — an error that is not a module-not-found
+error came from the package itself, so it is present by definition; then
+`import.meta.resolve()`, which answers "is the package there" without stating its
+entry file, unlike `createRequire().resolve()`). Only the genuinely-absent half
+is silent. The other prints an ordinary `HealthCheckResult` through the same
+renderer every other check uses:
+
+```
+  ⚠ Unique scope          Could not load the installed-package ledger reader (installed packages
+                          NOT checked for installation-wide uniques) — Cannot find module …
+```
+
+**Warning, not error**, and the exit code is unchanged, matching its two
+siblings: the environment still runs; what broke is doctor's ability to see part
+of it. The cause is quoted from the thrower, and `--verbose` expands it together
+with the remedy — reinstall, or build the package in a monorepo checkout.
+
+The row is **not** conditional on `.objectstack/installed-packages/` existing.
+Doctor cannot honestly say a ledger is absent when the constant naming the
+ledger's location is an export of the package that would not load.
+
+One consequence worth stating: in a monorepo checkout where
+`packages/cloud-connection` has not been built, `os doctor` under the `isolated`
+posture now prints this warning instead of a clean bill. That state is exactly
+what sent #5612 chasing a report face that had never regressed.