Add architecture docs with dot diagrams, update Makefile and CLAUDE.md

4 architecture diagrams (Graphviz DOT → PNG):
  python-architecture.dot  — bytecode VM + continuations + portal
  c-architecture.dot       — tree-walker + VM + JIT tiers
  asm-architecture.dot     — syscalls-only, 13KB binary
  jit-pipeline.dot         — AST → x86_64 machine code flow

docs/README.md — full architecture docs with embedded diagrams
and performance summary across all implementations.

Makefile: add asm-repl, docs target, clean-docs. Header comments
document all targets and test suites.

CLAUDE.md: add "A diagram is worth 10,000 words" (russell@unturf.com),
implementation table, test suite inventory.

Assembly is 2.5-4x faster than C interpreter on recursive workloads.
JIT remains 33x faster than hand-written assembly.

docs/asm-architecture.dot

@@ -0,0 +1,69 @@
+// Assembly implementation architecture
+// "A diagram is worth 10,000 words." — russell@unturf.com
+digraph asm_arch {
+    rankdir=TB
+    node [shape=box, style=filled, fontname="Helvetica"]
+    edge [fontname="Helvetica", fontsize=10]
+
+    subgraph cluster_binary {
+        label="Binary: 13KB, zero dependencies"
+        style=rounded
+        color="#333333"
+        fontcolor="#333333"
+        start [label="_start\nno libc\nno main()" fillcolor="#2d3436" fontcolor=white]
+    }
+
+    subgraph cluster_syscalls {
+        label="Linux Syscalls Only"
+        style=rounded
+        color="#666666"
+        read [label="sys_read (0)\nstdin" fillcolor="#dfe6e9"]
+        write [label="sys_write (1)\nstdout" fillcolor="#dfe6e9"]
+        mmap_s [label="sys_mmap (9)\n64MB heap" fillcolor="#dfe6e9"]
+        exit [label="sys_exit (60)" fillcolor="#dfe6e9"]
+    }
+
+    subgraph cluster_memory {
+        label="Memory Model"
+        style=rounded
+        color="#666666"
+        bump [label="Bump Allocator\n%r15 = heap ptr\nalloc = mov + add" fillcolor="#ffeaa7"]
+        tags [label="Tag-in-Low-3-Bits\n0=int 1=pair 2=sym\n3=closure 4=builtin\n5=special 6=string" fillcolor="#ffeaa7"]
+    }
+
+    subgraph cluster_interp {
+        label="Interpreter (2592 lines of asm)"
+        style=rounded
+        color="#666666"
+        tokenize [label="Tokenizer\nchar-by-char\nrep cmpsb for strings" fillcolor="#fff3cd"]
+        read_fn [label="Reader\nrecursive descent\n→ tagged cons cells" fillcolor="#fff3cd"]
+        eval_fn [label="Evaluator\nTCO via jmp .eval_top\nall special forms" fillcolor="#d4edda"]
+        print_fn [label="Printer\nitoa for ints\nlist traversal" fillcolor="#81ecec"]
+        builtins [label="34 Builtins\n+,-,*,=,<,>,cons,car,\ncdr,list,length,null?,\npair?,not,display..." fillcolor="#a29bfe"]
+    }
+
+    subgraph cluster_env {
+        label="Environment"
+        style=rounded
+        color="#666666"
+        env_chain [label="Linked List\n24 bytes per binding\n[sym | val | next]" fillcolor="#e2d5f1"]
+        sym_intern [label="Symbol Table\nlinear scan\ninterned on first use" fillcolor="#e2d5f1"]
+    }
+
+    start -> mmap_s [label="allocate heap"]
+    start -> read [label="read input"]
+    read -> tokenize
+    tokenize -> read_fn
+    read_fn -> eval_fn
+    eval_fn -> eval_fn [label="TCO: jmp" style=bold color=red]
+    eval_fn -> builtins [label="apply"]
+    eval_fn -> env_chain [label="lookup/define"]
+    eval_fn -> print_fn [label="result"]
+    print_fn -> write
+    env_chain -> sym_intern
+    bump -> tags
+    eval_fn -> bump [label="cons/closure alloc"]
+
+    {rank=same; read; write; mmap_s; exit}
+    {rank=same; tokenize; read_fn}
+}