tcl: Phase 6 coroutines + clock/file stubs + idiom corpus (+40 tests, 329 total)

- Coroutines (generator-style): coroutine/yield/yieldto commands; eager yield
  collection during body execution, pop-on-call dispatch via registered command
  closures; coro-yields + coroutines threaded through tcl-call-proc
- info exists varname (plus hostname/script/tclversion stubs)
- clock seconds/milliseconds/format/scan stubs
- File I/O stubs: open/close/read/eof/seek/tell/flush + file subcommands
- format command: full %-specifier parsing with flags, width, zero-pad, left-align
- Fixed dict set/unset/incr/append/update to use tcl-var-get (upvar alias aware)
- Fixed lappend and append to use tcl-var-get for reading (upvar alias aware)
- 20 coroutine tests (coro.sx) + 20 idiom corpus tests (idioms.sx)
- event-loop.tcl program: cooperative scheduler demo using coroutines
- Note: coroutines eagerly collect yields (generator-style, not true suspension)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/tcl/test.sh

@@ -20,11 +20,15 @@ cat > "$HELPER" << 'HELPER_EOF'
 (define __er (tcl-run-eval-tests))
 (define __xr (tcl-run-error-tests))
 (define __nr (tcl-run-namespace-tests))
+(define __cr (tcl-run-coro-tests))
+(define __ir (tcl-run-idiom-tests))
 (define tcl-test-summary
   (str "PARSE:" (get __pr "passed") ":" (get __pr "failed")
        " EVAL:" (get __er "passed") ":" (get __er "failed")
        " ERROR:" (get __xr "passed") ":" (get __xr "failed")
-       " NAMESPACE:" (get __nr "passed") ":" (get __nr "failed")))
+       " NAMESPACE:" (get __nr "passed") ":" (get __nr "failed")
+       " CORO:" (get __cr "passed") ":" (get __cr "failed")
+       " IDIOM:" (get __ir "passed") ":" (get __ir "failed")))
 HELPER_EOF
 
 cat > "$TMPFILE" << EPOCHS
@@ -43,16 +47,20 @@ cat > "$TMPFILE" << EPOCHS
 (epoch 7)
 (load "lib/tcl/tests/namespace.sx")
 (epoch 8)
-(load "$HELPER")
+(load "lib/tcl/tests/coro.sx")
 (epoch 9)
+(load "lib/tcl/tests/idioms.sx")
+(epoch 10)
+(load "$HELPER")
+(epoch 11)
 (eval "tcl-test-summary")
 EPOCHS
 
-OUTPUT=$(timeout 90 "$SX_SERVER" < "$TMPFILE" 2>&1)
+OUTPUT=$(timeout 180 "$SX_SERVER" < "$TMPFILE" 2>&1)
 [ "$VERBOSE" = "-v" ] && echo "$OUTPUT"
 
-# Extract summary line from epoch 9 output
-SUMMARY=$(echo "$OUTPUT" | grep -A1 "^(ok-len 9 " | tail -1 | tr -d '"')
+# Extract summary line from epoch 11 output
+SUMMARY=$(echo "$OUTPUT" | grep -A1 "^(ok-len 11 " | tail -1 | tr -d '"')
 
 if [ -z "$SUMMARY" ]; then
   echo "ERROR: no summary from test run"
@@ -60,11 +68,13 @@ if [ -z "$SUMMARY" ]; then
   exit 1
 fi
 
-# Parse PARSE:N:M EVAL:N:M ERROR:N:M NAMESPACE:N:M
+# Parse PARSE:N:M EVAL:N:M ERROR:N:M NAMESPACE:N:M CORO:N:M IDIOM:N:M
 PARSE_PART=$(echo "$SUMMARY"     | grep -o 'PARSE:[0-9]*:[0-9]*')
 EVAL_PART=$(echo "$SUMMARY"      | grep -o 'EVAL:[0-9]*:[0-9]*')
 ERROR_PART=$(echo "$SUMMARY"     | grep -o 'ERROR:[0-9]*:[0-9]*')
 NAMESPACE_PART=$(echo "$SUMMARY" | grep -o 'NAMESPACE:[0-9]*:[0-9]*')
+CORO_PART=$(echo "$SUMMARY"      | grep -o 'CORO:[0-9]*:[0-9]*')
+IDIOM_PART=$(echo "$SUMMARY"     | grep -o 'IDIOM:[0-9]*:[0-9]*')
 
 PARSE_PASSED=$(echo "$PARSE_PART"         | cut -d: -f2)
 PARSE_FAILED=$(echo "$PARSE_PART"         | cut -d: -f3)
@@ -74,21 +84,27 @@ ERROR_PASSED=$(echo "$ERROR_PART"         | cut -d: -f2)
 ERROR_FAILED=$(echo "$ERROR_PART"         | cut -d: -f3)
 NAMESPACE_PASSED=$(echo "$NAMESPACE_PART" | cut -d: -f2)
 NAMESPACE_FAILED=$(echo "$NAMESPACE_PART" | cut -d: -f3)
+CORO_PASSED=$(echo "$CORO_PART"           | cut -d: -f2)
+CORO_FAILED=$(echo "$CORO_PART"           | cut -d: -f3)
+IDIOM_PASSED=$(echo "$IDIOM_PART"         | cut -d: -f2)
+IDIOM_FAILED=$(echo "$IDIOM_PART"         | cut -d: -f3)
 
 PARSE_PASSED=${PARSE_PASSED:-0};         PARSE_FAILED=${PARSE_FAILED:-1}
 EVAL_PASSED=${EVAL_PASSED:-0};           EVAL_FAILED=${EVAL_FAILED:-1}
 ERROR_PASSED=${ERROR_PASSED:-0};         ERROR_FAILED=${ERROR_FAILED:-1}
 NAMESPACE_PASSED=${NAMESPACE_PASSED:-0}; NAMESPACE_FAILED=${NAMESPACE_FAILED:-1}
+CORO_PASSED=${CORO_PASSED:-0};           CORO_FAILED=${CORO_FAILED:-1}
+IDIOM_PASSED=${IDIOM_PASSED:-0};         IDIOM_FAILED=${IDIOM_FAILED:-1}
 
-TOTAL_PASSED=$((PARSE_PASSED + EVAL_PASSED + ERROR_PASSED + NAMESPACE_PASSED))
-TOTAL_FAILED=$((PARSE_FAILED + EVAL_FAILED + ERROR_FAILED + NAMESPACE_FAILED))
+TOTAL_PASSED=$((PARSE_PASSED + EVAL_PASSED + ERROR_PASSED + NAMESPACE_PASSED + CORO_PASSED + IDIOM_PASSED))
+TOTAL_FAILED=$((PARSE_FAILED + EVAL_FAILED + ERROR_FAILED + NAMESPACE_FAILED + CORO_FAILED + IDIOM_FAILED))
 TOTAL=$((TOTAL_PASSED + TOTAL_FAILED))
 
 if [ "$TOTAL_FAILED" = "0" ]; then
-  echo "ok $TOTAL_PASSED/$TOTAL tcl tests passed (parse: $PARSE_PASSED, eval: $EVAL_PASSED, error: $ERROR_PASSED, namespace: $NAMESPACE_PASSED)"
+  echo "ok $TOTAL_PASSED/$TOTAL tcl tests passed (parse: $PARSE_PASSED, eval: $EVAL_PASSED, error: $ERROR_PASSED, namespace: $NAMESPACE_PASSED, coro: $CORO_PASSED, idiom: $IDIOM_PASSED)"
   exit 0
 else
-  echo "FAIL $TOTAL_PASSED/$TOTAL passed, $TOTAL_FAILED failed (parse: $PARSE_PASSED/$((PARSE_PASSED+PARSE_FAILED)), eval: $EVAL_PASSED/$((EVAL_PASSED+EVAL_FAILED)), error: $ERROR_PASSED/$((ERROR_PASSED+ERROR_FAILED)), namespace: $NAMESPACE_PASSED/$((NAMESPACE_PASSED+NAMESPACE_FAILED)))"
+  echo "FAIL $TOTAL_PASSED/$TOTAL passed, $TOTAL_FAILED failed (parse: $PARSE_PASSED/$((PARSE_PASSED+PARSE_FAILED)), eval: $EVAL_PASSED/$((EVAL_PASSED+EVAL_FAILED)), error: $ERROR_PASSED/$((ERROR_PASSED+ERROR_FAILED)), namespace: $NAMESPACE_PASSED/$((NAMESPACE_PASSED+NAMESPACE_FAILED)), coro: $CORO_PASSED/$((CORO_PASSED+CORO_FAILED)), idiom: $IDIOM_PASSED/$((IDIOM_PASSED+IDIOM_FAILED)))"
   if [ -z "$VERBOSE" ]; then
     echo "--- output ---"
     echo "$OUTPUT" | tail -30