Integrate native Rime and stabilize input, output, and rendering

- Add optional modifier-only Super binding whose tap is cancelled by
  other input, focus changes, grabs, locks, and session teardown.
- Ship the native ferese-rime user service, Rime defaults, installer
  inventory, package dependencies, session environment, and docs.
- Vendor Smithay 8a27023 with the SHM texture-cache format fix and add
  GPU regressions for format changes and resize snapshots.
- Release reused CRTC owners before staging output modes, then restore
  changed outputs before former owners when a transaction fails.
- Wait for resize-capture GPU completion, expand filtered surface
  damage, and preserve IME popup origin under fractional scaling.
- Mark weekends like holidays in both calendar layouts.

vendor/smithay/CONTRIBUTING.md

@@ -0,0 +1,35 @@
+# Contributing
+
+Smithay is open to contributions from anyone. Here are a few tips to get started if you want to participate.
+
+## Coordination
+
+Most discussion about features and their implementations takes place on github.
+If you have questions, suggestions, ideas, you can open an issue to discuss it, or add your message in an already existing issue
+if it fits its scope.
+
+If you want a more realtime discussion I (@vberger) have a Matrix room dedicated to Smithay and
+my other wayland crates: [#smithay:matrix.org](https://matrix.to/#/#smithay:matrix.org). If you don't want to
+use matrix, this room is also bridged to libera.chat IRC on #smithay.
+
+## Scope
+
+Smithay attempts to be as generic and un-opinionated as possible. As such, if you have an idea of a feature that would be useful
+for your compositor project and would like it to be integrated in Smithay, please consider whether it is in its scope:
+
+- If this is a very generic feature that probably many different projects would find useful, it can be integrated in Smithay
+- If it is a rather specific feature, but can be framed as a special case of a more general feature, this general feature is
+  likely worth adding to Smithay
+- If this feature is really specific to your use-case, it is out of scope for Smithay
+
+## Structure
+
+Smithay aims to be a modular hierarchical library:
+
+- Functionalities should be split into independent modules as much as possible
+- There can be dependencies in functionalities
+- Even if most people would directly use a high-level functionality, the lower level abstractions it is built on should
+  still be exposed independently if possible
+
+The goal is for Smithay to be a "use what you want" library, and features that are not used should have no impact on the
+application built with Smithay.