feat(release,docs): M149 发布构建烘入微软登录 id（仓库 Secret），文档改为「官方构建开箱即用」

构建侧：release-build.yml 声明 on.workflow_call.secrets.ULL_MSA_CLIENT_ID（required: false），
cargo build 步以 env 注入它，option_env! 把它烘进二进制；release.yml 的 build job 按名显式透传
（与 PUBLISH_TOKEN 同一模式，不用 inherit）。真值放仓库 Secret，不进任何 git 文件；Secret 未录入
或 Actions 之外求值为空串时，client_id.rs 的 blank_env_value_counts_as_missing 保证「空白=没配」，
不会拿空 id 去联网。

文档：README 两版 / help.rs 的 accounts topic / packaging/release-notes.md /
packaging/docs/build-and-ci.md 统一成「官方构建已内置登录所需配置、开箱即用，仍可用环境变量
ULL_MSA_CLIENT_ID 覆盖；自建想自带就构建时注入」的功能性口径 —— 不出现 id 本身，也不出现归属描述。
client_id.rs 的模块注释与测试注释同步（原文写「id 不进仓库（用户定案）」，已随 Secret 方案改写），
并记下「别把 ULL_MSA_CLIENT_ID 导出到跑 cargo test 的 shell」——presenter 的 M132 入口锚会在
已烘焙 id 的构建里故意红。

实测：ULL_MSA_CLIENT_ID=<id> cargo build --bin ull 后，清空 env 跑 ull accounts add msa 打出
用户码与链接（无「未配置」提示）；同二进制设一个假 env id 则 AADSTS700016 点名该假 id（env 覆盖生效）。
单测：core auth 28、unlucky-cli 全套、i18n 30、presenter 222 全绿；M132 锚在烘焙构建里按设计红、
在不带 id 的构建里绿。cargo fmt --all --check 通过。

packaging/release-notes.md

@@ -100,14 +100,16 @@ Get-FileHash .\unlucky-launcher_{{VERSION}}_windows_x64.exe -Algorithm SHA256
 
 ## Known limitations of this build
 
-- Microsoft (MSA) sign-in needs an Azure public client id, and release binaries do not carry one: set
-  `ULL_MSA_CLIENT_ID=<id>` before launching, or build with that variable set. Without it sign-in stops
+- Microsoft (MSA) sign-in works out of the box: this build carries the Azure public client id it needs
+  (a public client id, not a credential — it ships inside the binary), so there is nothing to configure
+  before signing in. Setting `ULL_MSA_CLIENT_ID=<id>` before launching still overrides it; the variable
+  is read at startup, so restart the launcher after changing it. A build with no id anywhere stops
   before any network call, and the GUI banner says so plainly: the title "Microsoft sign-in is not
-  configured", a body naming `ULL_MSA_CLIENT_ID=<id>` (set it, or build with it, then restart the
-  launcher — a running process does not pick up a new variable) and `Code: msa_not_configured`, with
-  no Retry button. Every other sign-in failure keeps the generic banner plus its own `Code:` line,
-  with the full reason only in the launcher log. `ull accounts add msa` prints the same fix on the
-  command line. Offline profiles and authlib-injector servers need no id.
+  configured", a body naming `ULL_MSA_CLIENT_ID=<id>` (set it, or build with it, then restart) and
+  `Code: msa_not_configured`, with no Retry button. Every other sign-in failure keeps the generic
+  banner plus its own `Code:` line, with the full reason only in the launcher log. `ull accounts add
+  msa` prints the same fix on the command line. Offline profiles and authlib-injector servers need no
+  id.
 - Binaries are not code-signed / notarized yet: Windows SmartScreen and macOS Gatekeeper warn on first
   launch. The checksums above are the integrity reference for now.
 - When the macOS slot ships it is the bare binary (single-file promise), not a `.app` bundle: no Dock