docs: the tree has C dependencies, it links no system libraries

docs/core-concepts/architecture.md

@@ -66,5 +66,6 @@ Each of these is a thing telemetryd does not have, and the reason:
 - **No background compaction.** Segments are sealed once and never rewritten. That is
   most of the single-host ingest advantage: no merge amplification.
 - **No query planner.** The query shapes are known at compile time.
-- **No C dependencies at all.** Which is what makes the static musl builds a
-  straightforward link rather than a source of surprises.
+- **No system libraries.** The three C dependencies — zstd, `ring` and mimalloc — are
+  built from source and linked statically, so nothing is linked from the machine that
+  runs the binary and the static musl builds stay a straightforward link.

docs/extension-points/_index.md

@@ -53,6 +53,6 @@ that matters — anything speaking them works within the documented subset.
 **Scrape its self-metrics.** `/metrics` is Prometheus exposition; `/status` is JSON with
 disk usage, retention activity, per-signal counts and recovery events.
 
-**Fork it.** MIT, roughly ten thousand lines, no C dependencies. The doc comments
+**Fork it.** MIT, roughly ten thousand lines, no system libraries. The doc comments
 explain why each piece is the way it is, including where the original plan turned out
 to be wrong.

docs/getting-started/installation.md

@@ -149,8 +149,8 @@ cd telemetryd
 cargo build --release
 ```
 
-Needs Rust 1.89 or newer and a C compiler: zstd and `ring`, the TLS library's
-cryptography, are built from C and assembly. Nothing is linked from the system — the
+Needs Rust 1.89 or newer and a C compiler: zstd, `ring` (the TLS library's
+cryptography) and mimalloc (the allocator) are built from C and assembly. Nothing is linked from the system — the
 release binaries are static — so there is no library to install on the machine that runs
 it.
 

docs/requirements.md

@@ -64,7 +64,7 @@ Stated because these are the dependencies comparable systems do need:
 | | |
 |---|---|
 | Rust | 1.89 or newer, stable |
-| C toolchain | None. There are no C dependencies in the tree at all, which is what keeps the static musl builds straightforward |
+| C toolchain | A C compiler. zstd, `ring` (the TLS library's cryptography) and mimalloc (the allocator) are built from C, and linked statically: the binary still needs no library on the machine that runs it |
 
 ```bash
 cargo build --release