Infrastructure: Implement master/dev/vX branching, save git path, and fix username casing

AI_RULES.md

@@ -16,6 +16,11 @@ Any AI or session MUST respect these mandatory rules.
 ## Implementation Completion
 - All code modifications MUST be committed in git before the task is considered finished. `VERSION.json` must be updated on EACH commit.
 - **MANDATORY GIT RULE:** Never push to remote unless explicitly requested by the user. Only commit locally with proper messages. Always assume the user will handle all `git push` operations. If a task requires pushing, ask for explicit permission first.
+- **GIT BINARY PATH**: On this macOS environment, the system `git` (in `/usr/bin/git`) is often broken due to `xcode-select` issues. ALWAYS use the binary path stored in `.git_path` at the project root for all Git operations.
+- **GIT BRANCHING STRUCTURE**:
+    - The main stable branch is `master`.
+    - All active development MUST occur in the `dev` branch.
+    - Every major version MUST have its own dedicated archival branch named `vX` (e.g., `v1`, `v2`) which copies the state of the major release.
 - **MANDATORY GIT RULE**: NO AI is allowed to write in git commits that it is the author or co-author (e.g., DO NOT add texts like `Co-Authored-By: AI...`). Commits should only contain technical messages.
 - **MANDATORY LOGGING**: Any modification of code, architecture, or logic MUST be documented in `dev_docs/ARCHIVE_LOGS.md` at the end of the task. The log must include modified files, purpose of modification, and (if applicable) test results.
 - **MANDATORY PLAN ARCHIVING**: Once a phase or task is confirmed as completed and verified, the Architect (Gemini/AI) MUST move these entries from `PLAN.md` into `dev_docs/PLAN_HISTORY.md`. This maintains the active plan's focus and prevents document bloat.