fix: editor split, stop flag in actions, write errors, history on failure, expect panic, string match

- src/main.rs: split VISUAL/EDITOR into prog+args, drop expect panic in reap_timer, propagate write_timer errors, check stop during actions, record history on partial failure, use const for stop msg
- Cargo.toml: add authors/homepage, bump noyalib 0.0.12->0.0.13
- release.yaml: tighten tag glob, fix curl 404 fallback, URI-encode asset name, upgrade upload-artifact v3->v4
- ci.yaml: add cargo cache step
- README.md: sync feature list, fix push to two-step
- RELEASING.md: clarify Cargo.lock regeneration

RELEASING.md

@@ -52,7 +52,7 @@ version=1.1.4
 Update:
 
 - `Cargo.toml`: `package.version`
-- `Cargo.lock`: package version, regenerated by Cargo
+- `Cargo.lock`: run `cargo build --release` (without `--locked`) to regenerate
 - `VERSION`
 - `CHANGELOG.md`