fix(m163): push tag 默认建稳定版（发布标记语义 + 0.2.3 bump）

发布标记：`release.yml` 的 dispatch `prerelease` 默认值 true → false；`release-publish.yml`
的 create 路径不再塞 `--prerelease`（空串 = push tag ⇒ 稳定版），edit 路径行为不变（空串不碰
标记）。三种触发各创建什么改由 `packaging/release_marker.py` 一张表定义，流水线
`--emit-bash` 出来两个数组直接用，自己不再写 case——v0.2.2 至今 `releases/latest` 404 的根因
就是「push 默认 prerelease」这层叠上「dispatch 默认 true」。

守门：新增 `packaging/check_release_semantics.py`（CI 在 `.github/workflows/release-guard.yml`，
guards.yml 已 398 行不能再挂 job）：①标记表逐条对（push tag 的 create 不含 --prerelease）；
②把 `--emit-bash` 真灌进 bash 读回两个数组；③publish 的可执行内容里没有 --prerelease 字面量、
必须调用 emit-bash、两个数组各喂 create/edit；④release.yml 的 dispatch 默认值 == false（读
YAML 结构）。`--self-mutation` 注入三项真实回归（默认值改回 true / 塞回字面量 / 表里 push
改成预发布），断言每项都红、基线绿。

版本：0.2.2 → 0.2.3（workspace `[workspace.package]` + 五处 path 依赖 pin + Cargo.lock）。

文档：README 中英两版版本行改 0.2.3，并把本阶段能力补进现有章节（Modrinth 匿名在线内容源、
自更新与稳定通道、整合包导入逐文件决策、实例级启动参数），删掉「没有自动更新通道」「导入只有
两份全局策略」两条过期说法；`release-notes.md` 写 0.2.3 的真实更新摘要（保留 {{VERSION}} /
{{SUMS}}）；`packaging/README.md` 与 `docs/build-and-ci.md` 里「push 默认仍 prerelease」的旧口径
全部改掉。

README.md

@@ -4,6 +4,8 @@
 
 > **Official project home**: <https://github.com/AskaEth/Unlucky-Launcher> ｜ downloads, issues and
 > release notes all live there: <https://github.com/AskaEth/Unlucky-Launcher/releases>
+>
+> **Version in this README: `0.2.3`** — `unlucky-launcher --version` prints the same number.
 
 Unlucky Launcher is a free, open-source **Minecraft: Java Edition** launcher written in Rust
 (Apache-2.0). It ships as **one native binary per platform** — no installer, no bundled runtime, no
@@ -43,6 +45,14 @@ gap: the reason text is still raw Chinese straight out of the launch layer (see
 - **Launching** — a 10-stage command-line assembly (`crates/core/src/launch/`), per-instance JVM and
   game arguments, a native-library pass, and a JSONL session record for every run. Process trees are
   killed as trees, not as one PID.
+- **Per-instance launch arguments** — JVM arguments, game arguments, memory, the Java executable and
+  the graphics backend (`default` / `opengl` / `vulkan`) live in the instance file under `launch.*`,
+  and every field falls back on its own: instance → global setting → factory default, so an instance
+  that only sets memory does not wipe the global JVM arguments. JVM arguments are *appended* (global
+  first, instance last, so the JVM's last-one-wins rule makes the instance win). An out-of-range
+  memory value counts as "not set" instead of producing `-Xmx0m`, an empty field means "follow", and
+  the backend row only appears for game versions that have it. The CLI and the GUI read the same
+  resolved values (`crates/core/src/game/launch_overrides.rs`).
 - **Crash diagnosis is real and local** — `crates/core/src/diagnose` collects five kinds of signals
   (exit code, `latest.log`, `crash-reports`, `hs_err_pid` files, environment snapshot including the
   mod list), matches them against a YAML rule set, and shows the findings with fix actions on the
@@ -56,8 +66,17 @@ gap: the reason text is still raw Chinese straight out of the launch layer (see
   export as `.mrpack` or a CurseForge manifest. Cancelling an **import** is interface-level only: the
   panel closes and the result is discarded, but the import thread runs to the end, because `core`'s
   import request has no cancel token yet (`crates/presenter/src/host/addon/pack.rs:28-42`).
+- **Import conflicts are decided per file** — before anything is written, the scan lists every
+  conflicting file (what it is, why it conflicts, how big it is) in pages of 40, and three entries
+  decide the batch: keep all, overwrite all, or choose per item — unpicked rows stay on "keep". Files
+  that do not conflict are never rewritten, and the report still names every conflict afterwards.
 - **Content library** — modpacks / mods / resource packs / shaders with keyword, source, version,
   loader and sort filters, paged results, and one-click *install into this instance*.
+- **Online source: Modrinth, anonymously** — search goes through `/v2/search` with facets taken from
+  the target instance (project type, game version, loader); project details and version lists follow,
+  and a remote entry whose hash is known is completed through `/v2/version_file/<hash>`. No API key,
+  and no POST: the download engine has no request-body field, so hashes are looked up one GET at a
+  time. Being offline is its own state — "not connected" — never "no matching content".
 - **What that page will refuse, and says so on the row** — a modpack cannot be installed *from* the
   library (packs go through the import pipeline above); CurseForge's *install* is disabled because
   its file endpoint is not wired; and an item whose game version or loader does not match the target
@@ -160,14 +179,42 @@ The dispatch rule is deliberately narrow, so nothing that used to work changed m
 that its typo took effect. The subcommand table lives in exactly one place
 (`crates/cli/src/cli/parse.rs`), so both binaries accept the same set by construction. `ull --help`
 lists them all: `instances`, `install`, `launch`, `pack import`, `accounts`, `sessions`, `logs`,
-`diag`, `config`, `java`, `agent`, `version`, `help`.
+`diag`, `config`, `java`, `update`, `agent`, `version`, `help`.
+
+### Updates, and the stable channel
+
+- **Self-update is real, and GUI and CLI share one core.** The settings panel's Update group and
+  `ull update check` / `ull update apply` both build the same `core::update::Job`
+  (`crates/core/src/update/`): fetch the manifest at `releases/latest/download/manifest.json`, compare
+  versions, admit the channel, verify length + SHA256, then swap the binary atomically — rename the
+  old file aside, move the new one in, roll back if that fails. A running Windows exe can be
+  *renamed* but not overwritten, which is why the swap is a rename.
+- **Four outcomes, never conflated**: up to date / update available / a newer version exists but ships
+  no artifact for this platform / the check itself failed (offline, broken manifest, channel
+  mismatch). A failed check is never reported as "up to date".
+- **Only the stable channel is published.** `update.channel` defaults to `stable`; beta / alpha /
+  nightly are modelled and reserved. A manifest is admitted only when both its declared channel and
+  the version's own pre-release stage agree — a manifest can lie, a version number cannot.
+- **Why a release has to be marked stable**: `releases/latest/download/*` only points at the newest
+  **non-prerelease** release, and the manifest address is pinned there. `0.2.3` is the first release
+  created without the pre-release flag (`0.2.2` stays a historical pre-release). Which trigger creates
+  which marker — push tag ⇒ stable, dispatch `prerelease=true` ⇒ pre-release — is one table
+  (`packaging/release_marker.py`), with a guard over it (`packaging/check_release_semantics.py`).
+- **Nothing installs itself behind your back.** The check at startup can be turned off
+  (`update.auto_check`, the same key the CLI reads), and installing is a button or an explicit
+  `ull update apply`. Debug builds can rehearse the whole chain against a local directory source
+  (`ULL_UPDATE_DIR`); release builds do not contain that path at all.
 
 ### Not done yet
 
 This list is the reason to believe the rest. None of it is hidden behind marketing copy.
 
-- **No installer and no auto-update channel.** You download a file and run it. Nothing checks for a
-  newer version for you, and there is no update source decided yet.
+- **No installer.** You download a file and run it — there is no setup step, and updates replace that
+  file in place instead of installing anything (see [Updates](#updates-and-the-stable-channel)).
+- **The update path has only been exercised against a local directory source.** The whole chain
+  (manifest → download → SHA256 → rename/rollback) ran with a debug build and a fixture, because the
+  real `releases/latest/download/manifest.json` was unreadable while `0.2.2` was still a pre-release.
+  The first observation on the live stable channel happens after `0.2.3` ships.
 - **Several buttons are placeholders.** On the instances page: *New instance*, *Import*, *Duplicate*,
   *Open folder*, *Delete*. On the logs page: *Open folder*. In the settings frame: *Save*, *Reset
   section*, *Add override*. Each writes `[page] 占位动作 …` to stderr and changes nothing — instance
@@ -190,8 +237,6 @@ This list is the reason to believe the rest. None of it is hidden behind marketi
   launch layer (`crates/core/src/launch/exit_analysis.rs`) instead of a reason code the UI could
   translate — which is exactly the `静默失败` you can see in the English screenshot above.
 - **The in-app assistant has no model behind it** (see above). The MCP server does.
-- **Pack import has two global policies**, keep-user or overwrite, not a per-file choice; the import
-  report lists every conflict so nothing is overwritten silently.
 - **Install progress is stage-level**, not byte-level, on the content-library install path.
 - **No native file chooser.** Import takes drag-and-drop or a pasted path.
 - **Android/Termux is experimental and not promised**: no released asset targets it. A GUI build is
@@ -297,6 +342,7 @@ merge. The macOS probe is not there yet — manual dispatch only, result recorde
 | `.github/workflows/ci.yml` | fmt + clippy + test + release build (Windows / Linux matrix); Linux runtime smoke (Xvfb, one real frame, PNG asserted non-blank); macOS runtime probe (manual dispatch only) |
 | `.github/workflows/guards.yml` | zero-UI guards (`crates/core`, `crates/presenter`, `crates/design`), 400-lines-per-file guard, cargo-deny licence and source guard |
 | `.github/workflows/release.yml` | tag `v*` → build both Windows slots (`windows-x64` + `windows-arm64`) on native runners → single-file artifacts + `SHA256SUMS.txt` → GitHub Release (publishes `windows-x64` only; `-f all_slots=true` builds all six slots for evidence) |
+| `.github/workflows/release-guard.yml` | release-marker semantics: push tag ⇒ a **stable** release, dispatch `prerelease=true` ⇒ pre-release; the table lives in `packaging/release_marker.py` and the guard mutation-tests itself |
 
 ## Architecture and module map