Implement SSH receive-pack pushes

docs/configuration.md

@@ -97,7 +97,8 @@ configuration, try additional keys, prompt for passwords or
 keyboard-interactive authentication, launch an agent, or invoke proxy/helper
 commands. In builds with the `ssh` feature, the same configuration drives
 branch discovery, clone, fetch, and pull over the embedded upload-pack channel;
-push support is enabled separately when receive-pack is available.
+push and full pull-then-push synchronization use the matching embedded
+receive-pack channel.
 
 The typed endpoint model is always available so an SSH remote remains readable
 through the Rust API even when the binary was built without SSH. Such a build

docs/git-synchronization.md

@@ -80,6 +80,18 @@ verification, object limits, and atomic ref updates, while the existing
 IronStorage code continues to own clone staging, checkout, merge, conflict, and
 rollback behavior.
 
+SSH push opens the same verified and authenticated session-channel boundary for
+`git-receive-pack '<path>'`. Storage validates the advertisement, rejects
+non-fast-forward updates before sending, constructs the complete reachable
+object pack, then half-closes channel input and drains the status and bounded
+stderr streams. The remote-tracking ref advances only after `unpack ok`, an
+`ok` for the selected ref, a zero service exit, and clean channel completion.
+Unpack and ref-policy rejections remain typed failures; a malformed response,
+disconnect, or cancellation after sending is an unknown outcome that requires
+a fresh fetch before retrying and is never replayed automatically. Synchronize
+always completes pull first and cannot open receive-pack after a failed,
+cancelled, or conflicted pull.
+
 Pull refuses a dirty worktree. It fast-forwards when possible and otherwise
 uses the embedded three-way tree merge. Unresolved paths are returned as typed
 `MergeConflicts`; no conflict markers or partial checkout are written. Checkout