feat: add mcpplibs.tinyhttps 0.2.1 + mcpplibs.llmapi 0.2.4 descriptors

Both upstream packages ship their own `mcpp.toml` from these versions
onwards, so Form A descriptors are sufficient — no inline `mcpp = {}`
segment needed.

mcpplibs.tinyhttps 0.2.1 — first tag containing mcpp manifest
  url     https://github.com/mcpplibs/tinyhttps/archive/refs/tags/0.2.1.tar.gz
  sha256  88adc68b1c1ec635c409604547fdfe8486aa1b376bad28c74858ed1f3ce5391c

mcpplibs.llmapi 0.2.4 — first tag containing mcpp manifest
  url     https://github.com/mcpplibs/llmapi/archive/refs/tags/0.2.4.tar.gz
  sha256  b1d204576ee2d2069abdac1a7e25078e605c8fae5b1cdad6cee200946cfed0f0

End-to-end smoke verified locally: `mcpp build` of llmapi pulls
mbedtls + tinyhttps from the index, compiles all module interfaces +
108 mbedtls .c files, and packs into a 4.5 MB libllmapi.a (125
objects).

Author: Sunrisepeak

pkgs/m/mcpplibs.llmapi.lua

@@ -0,0 +1,32 @@
+-- Form A descriptor: the upstream repo ships its own mcpp.toml from
+-- v0.2.4 onwards. mcpp's default-look-up walks the GitHub tarball
+-- wrap (`llmapi-<tag>/mcpp.toml`) automatically.
+package = {
+    spec        = "1",
+    name        = "mcpplibs.llmapi",
+    description = "Modern C++ LLM API client with openai-compatible support",
+    licenses    = {"Apache-2.0"},
+    repo        = "https://github.com/mcpplibs/llmapi",
+    type        = "package",
+
+    xpm = {
+        linux = {
+            ["0.2.4"] = {
+                url    = "https://github.com/mcpplibs/llmapi/archive/refs/tags/0.2.4.tar.gz",
+                sha256 = "b1d204576ee2d2069abdac1a7e25078e605c8fae5b1cdad6cee200946cfed0f0",
+            },
+        },
+        macosx = {
+            ["0.2.4"] = {
+                url    = "https://github.com/mcpplibs/llmapi/archive/refs/tags/0.2.4.tar.gz",
+                sha256 = "b1d204576ee2d2069abdac1a7e25078e605c8fae5b1cdad6cee200946cfed0f0",
+            },
+        },
+        windows = {
+            ["0.2.4"] = {
+                url    = "https://github.com/mcpplibs/llmapi/archive/refs/tags/0.2.4.tar.gz",
+                sha256 = "b1d204576ee2d2069abdac1a7e25078e605c8fae5b1cdad6cee200946cfed0f0",
+            },
+        },
+    },
+}

pkgs/m/mcpplibs.tinyhttps.lua

@@ -0,0 +1,32 @@
+-- Form A descriptor: the upstream repo ships its own mcpp.toml from
+-- v0.2.1 onwards, so we omit the `mcpp` field — mcpp default-look-up
+-- finds <verdir>/<repo-tag>/mcpp.toml inside the GitHub tarball wrap.
+package = {
+    spec        = "1",
+    name        = "mcpplibs.tinyhttps",
+    description = "Minimal C++23 HTTP/HTTPS client with SSE streaming support",
+    licenses    = {"Apache-2.0"},
+    repo        = "https://github.com/mcpplibs/tinyhttps",
+    type        = "package",
+
+    xpm = {
+        linux = {
+            ["0.2.1"] = {
+                url    = "https://github.com/mcpplibs/tinyhttps/archive/refs/tags/0.2.1.tar.gz",
+                sha256 = "88adc68b1c1ec635c409604547fdfe8486aa1b376bad28c74858ed1f3ce5391c",
+            },
+        },
+        macosx = {
+            ["0.2.1"] = {
+                url    = "https://github.com/mcpplibs/tinyhttps/archive/refs/tags/0.2.1.tar.gz",
+                sha256 = "88adc68b1c1ec635c409604547fdfe8486aa1b376bad28c74858ed1f3ce5391c",
+            },
+        },
+        windows = {
+            ["0.2.1"] = {
+                url    = "https://github.com/mcpplibs/tinyhttps/archive/refs/tags/0.2.1.tar.gz",
+                sha256 = "88adc68b1c1ec635c409604547fdfe8486aa1b376bad28c74858ed1f3ce5391c",
+            },
+        },
+    },
+}