fix(pkgs): chriskohlhoff.asio name 回归 FQN 形式 + lint 守卫 (mcpp#278)

#109 把 pkgs/c/chriskohlhoff.asio.lua 的 name 从 "chriskohlhoff.asio"
改成 "asio"(namespace 不变),这是该 commit 对描述符的唯一功能性改动,
其余全是注释重写。结果三平台 workspace job 全部在 tests/examples/asio-module
上失败:

  E_NOT_FOUND: package 'chriskohlhoff:chriskohlhoff.asio@1.38.1' not found

原因是 mcpp 内部两条规则对同一份描述符的口径不一致:身份归一化层
(manifest/xpkg.cppm canonical_xpkg_identity)认为 split 形式
(namespace="chriskohlhoff" + name="asio")与 FQN 形式等价、都合法,
而安装目标构造层(build/prepare.cppm)硬假设 name 字面值就等于
ns + "." + shortName。xlings/libxpkg 按前者的 name 字面值建索引 key
(entries[package.name] = "asio"),mcpp 却拿 "chriskohlhoff.asio" 去点名,
两者永远不相交。

实测四种消费端写法(点式选择器、ns 表内点式、default 索引裸名、别名索引
裸名)全部无解 —— ns 被身份闸门钉死、短名被 xpm 版本表钉死,fqname 恒为
chriskohlhoff.asio 而 key 恒为 asio。等价约束是 name 必须 ==
namespace + "." + <短名>,只能在描述符里修。

改动:

* pkgs/c/chriskohlhoff.asio.lua — name 写回 FQN 形式(与索引内其余 47 个
  namespaced 包一致)。文件路径、namespace、消费端 mcpp.toml 均不动。
* pkgs/t/tensorvia-cpu.lua — 同类隐患(ns="aimol" + name="tensorvia-cpu"),
  今天没被任何 workspace member 消费所以没暴露,但同样装不上;一并修正。
  该文件是 `mcpp emit xpkg` 生成后手工补了 namespace 才落入 split 形式。
* tests/check_package_name.lua + validate.yml rule 5 — namespace 非空时
  强制 name 以 "<namespace>." 开头。lint 秒级拦下,不再让这类错误跑满
  三平台一小时后才炸。

验证(CI 钉住的 mcpp 0.0.102 + vendored xlings 0.4.67,冷 store 冷索引缓存):
tests/examples/asio-module → 5 passed; 0 failed。lint 全量重放 exit 0,
负向测试(把 name 改回 split 形式)如期报错。

上游已提 mcpp-community/mcpp#278:mcpp 要么构造 target 时用描述符声明的
name(loadVersionDep 里 luaContent 已在作用域内),要么收紧规范让
`mcpp xpkg parse` 直接拒绝 split 形式。本 lint 是上游对齐前索引侧的守卫。

Author: Sunrisepeak

.github/workflows/validate.yml

@@ -90,7 +90,18 @@ jobs:
             if ! lua5.4 tests/check_mirror_urls.lua "$f"; then
               fail=1
             fi
-            # 5. c++fly admission policy (mcpp design 2026-07-14 §11-Q2, v1):
+            # 5. `name` must be the fully-qualified `<namespace>.<short>`.
+            #    The split form (namespace = "chriskohlhoff", name = "asio")
+            #    parses and passes `mcpp xpkg parse`, but xlings keys the index
+            #    on the literal `name` while mcpp asks for the reconstructed
+            #    FQN — they never meet, so the package is uninstallable on
+            #    every platform (mcpp-community/mcpp#278). This check is cheap
+            #    and catches in seconds what otherwise fails an hour into the
+            #    workspace job.
+            if ! lua5.4 tests/check_package_name.lua "$f"; then
+              fail=1
+            fi
+            # 6. c++fly admission policy (mcpp design 2026-07-14 §11-Q2, v1):
             #    c++fly means "toolchain's latest level + every experimental
             #    gate" — deliberately toolchain-dependent, so a published
             #    package built with it is not reproducible for consumers.

pkgs/c/chriskohlhoff.asio.lua

@@ -38,7 +38,15 @@
 package = {
     spec        = "1",
     namespace   = "chriskohlhoff",
-    name        = "asio",
+    -- `name` MUST be the fully-qualified `<namespace>.<short>`: xlings keys its
+    -- index on this literal (libxpkg build_index → entries[package.name]),
+    -- while mcpp asks for the FQN it reconstructs from the consumer's
+    -- `[dependencies.<ns>] <short>`. Writing the split form ("asio") is legal
+    -- per mcpp's own descriptor spec (manifest/xpkg.cppm canonical_xpkg_
+    -- identity normalizes both spellings) but registers the index entry under
+    -- `asio`, which no consumer request can ever hit → E_NOT_FOUND at install.
+    -- See mcpp-community/mcpp#278; the lint in validate.yml enforces this.
+    name        = "chriskohlhoff.asio",
     description = "Standalone asio exposed as the C++23 module `asio` (separate compilation)",
     licenses    = {"BSL-1.0"},
     repo        = "https://github.com/chriskohlhoff/asio",

pkgs/t/tensorvia-cpu.lua

@@ -1,8 +1,15 @@
 -- AUTO-GENERATED by `mcpp emit xpkg`. Do not edit by hand.
 -- Source: mcpp.toml @ v0.1.1
+--
+-- Hand-edit on top of the generated file: `mcpp emit xpkg` writes the bare
+-- project name and no `namespace`; the `namespace = "aimol"` line below was
+-- added when the package was filed into this index, which made `name` the
+-- split form and left the package uninstallable (xlings keyed the entry under
+-- `tensorvia-cpu` while mcpp asks for `aimol.tensorvia-cpu`). `name` is now
+-- the fully-qualified spelling. See mcpp-community/mcpp#278.
 package = {
     spec = "1",
-    name = "tensorvia-cpu",
+    name = "aimol.tensorvia-cpu",
     description = "CPU backend of Tensorvia, ported to C++23 modules",
     licenses = {"MIT"},
     repo = "https://github.com/Aimol-l/Tensorvia-cpu",

tests/check_package_name.lua

@@ -0,0 +1,77 @@
+-- Lint `package.name` against `package.namespace`.
+--
+-- Rule: a namespaced descriptor MUST spell `name` as the fully-qualified
+-- `<namespace>.<short>`. The split form (namespace = "chriskohlhoff",
+-- name = "asio") parses fine and passes `mcpp xpkg parse` — mcpp's own
+-- identity layer normalizes both spellings to the same package — but it is
+-- NOT installable from an index:
+--
+--   * xlings/libxpkg keys the index on the literal `package.name`
+--     (libxpkg build_index → entries[package.name]), so the entry lands
+--     under `asio`;
+--   * mcpp asks xlings for the FQN it reconstructs from the consumer's
+--     `[dependencies.<ns>] <short>`, i.e. `chriskohlhoff.asio`
+--     (mcpp src/build/prepare.cppm — "xlings resolves packages by the full
+--     qualified name (ns.shortName) as it appears in the index's name field").
+--
+-- The two never meet → E_NOT_FOUND at install time, on every platform, after
+-- the workspace job has already burned an hour. No consumer-side spelling can
+-- work around it; the descriptor is the only place it can be fixed.
+--
+-- Upstream: mcpp-community/mcpp#278 (mcpp should either use the declared name
+-- or reject the split form in `mcpp xpkg parse`). Until that lands, this lint
+-- is the index's guard.
+--
+-- Zero-namespace packages (the public default-namespace module packages —
+-- imgui / ffmpeg / opencv) are unaffected: their bare `name` IS the FQN.
+--
+-- Usage: lua5.4 tests/check_package_name.lua <file.lua>
+
+function import(...)
+    return setmetatable({}, {__index = function() return function() end end})
+end
+
+local path = assert(arg[1], "usage: check_package_name.lua <file>")
+package = nil
+local chunk = assert(loadfile(path, "t"))
+chunk()
+
+local p = package
+if type(p) ~= "table" then os.exit(0) end
+
+local fail = 0
+local function err(msg)
+    io.stderr:write(string.format("::error file=%s::%s\n", path, msg))
+    fail = 1
+end
+
+local name = p.name
+local ns   = p.namespace or ""
+
+if type(name) ~= "string" or name == "" then
+    err("package.name must be a non-empty string")
+    os.exit(fail)
+end
+if type(ns) ~= "string" then
+    err("package.namespace must be a string")
+    os.exit(fail)
+end
+
+if ns ~= "" then
+    local prefix = ns .. "."
+    if name:sub(1, #prefix) ~= prefix then
+        err(string.format(
+            "package.name must be the fully-qualified '<namespace>.<short>': " ..
+            "namespace = %q but name = %q — write name = %q. " ..
+            "The split form registers the index entry under %q, which no " ..
+            "consumer request can ever resolve (E_NOT_FOUND at install). " ..
+            "See mcpp-community/mcpp#278.",
+            ns, name, prefix .. name, name))
+    elseif #name == #prefix then
+        err(string.format(
+            "package.name = %q has an empty short name after the %q prefix",
+            name, prefix))
+    end
+end
+
+os.exit(fail)