chore: bump to 3.11.0 for the directory-output guard

The guard changes build_targets_list() behavior — it can now fail the build — so
it needs a version and a NEWS entry rather than riding along unversioned.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NYLFocBGCeJGjeRzAR8szX

Author: bbest

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: calcofi4db
 Title: CalCOFI Database Tools
-Version: 3.10.0
+Version: 3.11.0
 URL: https://calcofi.io/calcofi4db
 BugReports: https://github.com/calcofi/calcofi4db/issues
 Authors@R: 

NEWS.md

@@ -1,3 +1,31 @@
+# calcofi4db 3.11.0
+
+## `build_targets_list()` refuses a directory `output:`
+
+Every pipeline target is `format = "file"`, so `targets` hashes whatever path the
+command returns. If that path is a **directory**, anything later written
+underneath it — by a downstream target, or by hand — moves the hash and leaves
+the owning target reported outdated forever.
+
+`release_database` shipped in that state: it declared `data/releases`, and
+`test_release` writes `data/releases/{version}/test_results.json`. On
+v2026.08.08 the release's own files landed 16:46-17:06 and `test_results.json` at
+17:08:47, so the target went stale the moment the pipeline finished, and every
+subsequent `tar_make()` on it or anything downstream re-ran a ~40 minute freeze
+and a multi-GB re-upload of an already-promoted release.
+
+`check_nested_outputs()` now fails the build on any directory `output:`, and on
+one declared output nested inside another. Worth knowing why it checks what it
+checks: `test_release` declares `_output/test_release.html` and writes into
+`data/releases` as a **side effect**, so no comparison of the `output:` fields
+could ever have related the two — a first cut that only compared declared paths
+passed the real broken configuration. What *is* statically visible is that a
+target claimed a directory at all, and that is what is enforced.
+
+The fix for such a target is a single small file it alone writes — for the
+release, `data/releases/_release_stamp.json` carrying the version and a digest of
+the frozen catalog, deterministic so a no-op re-run does not cascade.
+
 # calcofi4db 3.10.0
 
 ## `declare_measurement_bounds()` — put a bound on a type that already exists