Add the GitHub and Gitea steps and split the script into library files

Dry run by default: the script reads from both hosts (tokens, owners,
names, license, SSH) and prints a plan; --apply creates the repositories
and the Gitea -> GitHub push mirror after a final yes. Choosing GitHub
applies the AGPL-3.0 license to the Gitea repository. A failed step is
reported with what exists and how to continue; nothing is ever deleted.

create-project.sh is now the entry point; the work lives in src/lib/, one
responsibility per file. .gitignore gets !src/lib (the Python template
ignores any lib/ folder). Tests grow to 599 checks, with a stub curl and
ssh, and guards for the file structure.

Task: MIL-002#1
Task: MIL-002#2
Task: MIL-002#3
Task: MIL-002#4
Task: MIL-002#5
Task: MIL-002#6
Refs #9
Refs #10
Refs #11
Refs #12
Refs #13
Refs #14

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

config.env.example

@@ -21,3 +21,11 @@ GITEA_URL=https://git.tirsystem.com/
 
 # Gitea REST API base URL. If you leave this out it is GITEA_URL + /api/v1.
 GITEA_API_URL=https://git.tirsystem.com/api/v1
+
+# Optional. SSH port of the Gitea server, used for the SSH check and later
+# for the framework submodule. Default: 10022.
+#GITEA_SSH_PORT=10022
+
+# Optional. How often Gitea pushes to GitHub, as a Go duration (10m0s, 8h0m0s).
+# The server may enforce a minimum. Default: 10m0s.
+#MIRROR_INTERVAL=10m0s