Add the local project, framework submodule, hooks and templates

After the repositories and the mirror, the script now creates the local
project: the directory, git on main, credential-free origin (and github)
remotes, and the license history from Gitea. Then it adds the framework as
a submodule over SSH, installs its skills and git hooks once (plan gate
optional), and copies the AGENTS.md and artifact registry templates.

Nothing is overwritten without a yes: an existing directory, core.hooksPath,
AGENTS.md or docs/artifact-registry.md each ask first (default no). Without
SSH the framework steps can only be skipped, after a yes. No commit is made
in the new project. New optional config key FRAMEWORK_REPO.

New library files git.sh, localproject.sh and framework.sh. Tests run real
git against local bare repositories that stand in for Gitea and the
framework, with a private git configuration (769 checks). The README is now
the full guide.

Task: MIL-003#1
Task: MIL-003#2
Task: MIL-003#3
Task: MIL-003#4
Task: MIL-003#5
Refs #15
Refs #16
Refs #17
Refs #18
Refs #19

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/lib/validate.sh

@@ -4,7 +4,7 @@
 #
 # Part of create-project.sh: sourced by it, never run on its own.
 #
-# Provides: is_valid_repo_name, is_valid_gitea_owner, is_valid_github_owner, is_valid_description, is_valid_directory, is_valid_base_url, is_valid_request_url, is_valid_token, is_valid_port, is_valid_interval, normalize_url
+# Provides: is_valid_framework_repo, is_valid_repo_name, is_valid_gitea_owner, is_valid_github_owner, is_valid_description, is_valid_directory, is_valid_base_url, is_valid_request_url, is_valid_token, is_valid_port, is_valid_interval, normalize_url
 
 is_valid_repo_name() {
   local name="$1"
@@ -49,6 +49,11 @@ is_valid_token() {
   [[ $1 =~ ^[A-Za-z0-9_.~+/=-]{8,255}$ ]]
 }
 
+# OWNER/NAME of the framework repository on Gitea.
+is_valid_framework_repo() {
+  [[ $1 =~ ^[A-Za-z0-9._-]+/[A-Za-z0-9._-]+$ && $1 != */.. && $1 != ../* && $1 != ./* && $1 != */. ]]
+}
+
 is_valid_port() {
   [[ $1 =~ ^[0-9]{1,5}$ ]] && ((10#$1 >= 1 && 10#$1 <= 65535))
 }