tcl: conformance.sh + scoreboard, annotate classic programs

Adds lib/tcl/conformance.sh: runs .tcl programs through the epoch
protocol, compares against # expected: annotations, writes
scoreboard.json and scoreboard.md. All 3 classic programs pass.

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

lib/tcl/tests/programs/assert.tcl

@@ -1,3 +1,4 @@
+# expected: 10
 proc assert {expr_str} {
     set result [uplevel 1 [list expr $expr_str]]
     if {!$result} {

lib/tcl/tests/programs/for-each-line.tcl

@@ -1,3 +1,4 @@
+# expected: 13
 proc for-each-line {var lines body} {
     foreach item $lines {
         uplevel 1 [list set $var $item]

lib/tcl/tests/programs/with-temp-var.tcl

@@ -1,3 +1,4 @@
+# expected: 100 999
 proc with-temp-var {varname tempval body} {
     upvar 1 $varname v
     set saved $v