iter emit-ir-staticlib: ail emit-ir --emit=staticlib (M1 fieldtest spec_gap#2)

Restores the Decision-5 IR-readability affordance for main-free
kernels: ail emit-ir gains --emit=staticlib, symmetric with
ail build, reusing the M1-audited Target::StaticLib path via a new
one-line lower_workspace_staticlib convenience. Zero-export guard
byte-identical to build_staticlib's. DESIGN.md widened (not
narrowed) + a pre-existing M1 synopsis omission corrected. 3 new
E2E tests; no fixture minted, no doc pin (E2E is the coverage).
Plan 03493c9.

docs/DESIGN.md

@@ -2301,6 +2301,11 @@ canonical M1 export shape:
     (app + state (app * sample sample))))
 ```
 
+`ail emit-ir <module> --emit=staticlib` prints this kernel's LLVM
+IR (the external `@<sym>` forwarders, no `@main`) instead of the
+executable-path `main`-required rejection — the Decision-5
+IR-readability affordance for a `main`-free kernel.
+
 ## Data model
 
 The on-disk JSON-AST is what the toolchain hashes, typechecks, and
@@ -2606,8 +2611,8 @@ ail workspace <entry.ail.json>           — list all modules transitively reach
                                            `manifest --workspace` and `diff --workspace`
                                            extend single-module subcommands to workspaces)
 ail builtins                             — list built-in fns and effect ops
-ail emit-ir   <module>                   — writes .ll
-ail build     <module>                   — full pipeline → binary
+ail emit-ir   <module> [--emit=staticlib]  — writes .ll (staticlib: a main-free kernel's IR, no @main)
+ail build     <module> [--emit=staticlib]  — full pipeline → binary (staticlib: lib<entry>.a + libailang_rt.a)
 ail run       <module>                   — build + execute (tempdir), passthrough exit code
 ```