feat: replace git-release with makerelease.sh

Add a new release helper that supports clean-tree checks, dry-run mode, and semantic version increments from the latest tag. Remove the old git-release script and update project conventions to reflect the new release workflow.

.continue/rules/project.md

@@ -7,14 +7,19 @@ description: SSHRM project conventions
 - Keep shell scripts Bash-based when Bash is already used by the project.
 - Preserve the current behavior of the main scripts:
   - `sshrm`: remove an entry from `~/.ssh/known_hosts` by host name or by line number.
-  - `git-release`: handle releases from `dev` to `main`, create an annotated tag, and push commits and tags.
 - Keep user-facing messages short, clear, and in English.
-- Prefer minimal, focused changes that do not alter the intent of the existing scripts.
+- Prefer minimal, focused changes that do not alter the intent of the existing scripts, unless the script behavior is intentionally updated.
 - Maintain `.continue/rules/project.md` whenever project conventions or script behavior change.
 - `sshrm` is implemented as a small Bash script with helper functions, while preserving host and line-number removal behavior.
 - `sshrm` should print a short usage line, support `-h`/`--help`, and fail clearly on missing or invalid line-number input.
 
 # Project identity
 - Main script: `sshrm`
-- Release helper: `git-release`
 - License: GNU GPL v3
+
+git checkout "${TAGBRANCH}"
+git merge "${CURRENTBRANCH}"
+git push
+git tag -a "${VERSION}" -m "${MESSAGE}"
+git push --tags
+git checkout "${CURRENTBRANCH}"