fix(proof-suite): make the runner's awk POSIX-portable

`canonical-proof-suite-runner.sh` parsed the manifest with `\s` in its awk
patterns (`/^\s*\(entry$/`) — `\s` is a GNU-awk extension. Under `mawk` (the
default `awk` on Debian/Ubuntu and many CI/dev boxes) `\s` matches nothing, so
`parse_manifest` returns zero entries and the runner reports a silent
`Summary: 0/0 passing` while exiting 0 — i.e. it looks like it ran but checked
nothing.

Replace the three `\s` occurrences (two awk `(entry` matchers + one `grep -E`
status matcher) with POSIX `[[:space:]]`, which behaves identically under
mawk, gawk, and grep.

Verified with a locally-installed Rocq 9 + idris2 + agda: the runner now parses
all entries and reports `Summary: 35/37 passing` (the 2 not-passing are the
Coquelicot/mathcomp-dependent proofs whose sources are unreachable from this
host) — previously `0/0`.

https://claude.ai/code/session_018CaSgNjNURC7ocsyjYh9We

Author: claude

scripts/canonical-proof-suite-runner.sh

@@ -88,7 +88,7 @@ BANNED=(
 parse_manifest() {
   awk '
     BEGIN { id=""; domain=""; thm=""; prover=""; proof=""; sym=""; in_entry=0 }
-    /^\s*\(entry$/ { id=""; domain=""; thm=""; prover=""; proof=""; sym=""; in_entry=1; next }
+    /^[[:space:]]*\(entry$/ { id=""; domain=""; thm=""; prover=""; proof=""; sym=""; in_entry=1; next }
     in_entry && /\(id "/              { match($0, /"[^"]*"/); id     = substr($0, RSTART+1, RLENGTH-2) }
     in_entry && /\(domain "/          { match($0, /"[^"]*"/); domain = substr($0, RSTART+1, RLENGTH-2) }
     in_entry && /\(theorem "/         { match($0, /"[^"]*"/); thm    = substr($0, RSTART+1, RLENGTH-2) }
@@ -312,7 +312,7 @@ prior_status() {
   local id="$1"
   local sc="${SIDECAR_DIR}/${id}.sidecar.a2ml"
   if [ -f "${sc}" ]; then
-    grep -E '^\s*\(status "' "${sc}" 2>/dev/null \
+    grep -E '^[[:space:]]*\(status "' "${sc}" 2>/dev/null \
       | head -1 \
       | sed -E 's/.*"([^"]+)".*/\1/'
   else
@@ -480,7 +480,7 @@ TOTAL=$(wc -l < "${TMP_RESULTS}")
   echo "| ID | Theorem | Prover | Status | Semantic | Elapsed (ms)"
   while IFS=$'\t' read -r id status elapsed prover kernel proof sem; do
     thm=$(awk -v want="${id}" '
-      /^\s*\(entry$/ { in_e=1; next }
+      /^[[:space:]]*\(entry$/ { in_e=1; next }
       in_e && /\(id "/ { match($0, /"[^"]*"/); cur=substr($0,RSTART+1,RLENGTH-2) }
       in_e && /\(theorem "/ {
         match($0, /"[^"]*"/); t=substr($0,RSTART+1,RLENGTH-2)