fix(herdr): ensure unique agent name via sha1 truncation and align mock errors

- Replace legacy s[:16]-s[-15:] truncation with 8-char SHA-1 hash suffix in sanitize.py and lib.sh to prevent workspace name collisions
- Align mock Herdr error messages in tests/conftest.py to real Herdr 0.8.0 output format
- Add missing required/invalid_agent_name to early abort regex in lib.sh
- Remove legacy heuristics in lib.sh has-session and unify mock agent lookups
- Add unit tests in tests/test_sanitize_and_mock_errors.py (256/256 passed)

.agents/skills/lib.sh

@@ -36,9 +36,17 @@ _sanitize_herdr_agent_name() {
   s=$(echo "$n" | tr '[:upper:]' '[:lower:]' | sed -E 's/[^a-z0-9_-]/-/g')
   if [[ ! "$s" =~ ^[a-z] ]]; then s="x-$s"; fi
   if [ "${#s}" -gt 32 ]; then
-    local p="${s:0:16}"
-    local suf="${s: -15}"
-    s="${p}-${suf}"
+    local h=""
+    if command -v shasum >/dev/null 2>&1; then
+      h=$(printf '%s' "$s" | shasum 2>/dev/null | awk '{print $1}' | cut -c 1-8)
+    elif command -v sha1sum >/dev/null 2>&1; then
+      h=$(printf '%s' "$s" | sha1sum 2>/dev/null | awk '{print $1}' | cut -c 1-8)
+    elif command -v openssl >/dev/null 2>&1; then
+      h=$(printf '%s' "$s" | openssl sha1 2>/dev/null | awk '{print $NF}' | cut -c 1-8)
+    else
+      h=$(python3 -c "import hashlib,sys; print(hashlib.sha1(sys.argv[1].encode()).hexdigest()[:8])" "$s" 2>/dev/null || echo "00000000")
+    fi
+    s="${s:0:23}-${h}"
   fi
   printf '%s\n' "${s:0:32}"
 }
@@ -215,9 +223,17 @@ _sanitize_herdr_agent_name() {
   s=$(echo "$n" | tr '[:upper:]' '[:lower:]' | sed -E 's/[^a-z0-9_-]/-/g')
   if [[ ! "$s" =~ ^[a-z] ]]; then s="x-$s"; fi
   if [ "${#s}" -gt 32 ]; then
-    local p="${s:0:16}"
-    local suf="${s: -15}"
-    s="${p}-${suf}"
+    local h=""
+    if command -v shasum >/dev/null 2>&1; then
+      h=$(printf '%s' "$s" | shasum 2>/dev/null | awk '{print $1}' | cut -c 1-8)
+    elif command -v sha1sum >/dev/null 2>&1; then
+      h=$(printf '%s' "$s" | sha1sum 2>/dev/null | awk '{print $1}' | cut -c 1-8)
+    elif command -v openssl >/dev/null 2>&1; then
+      h=$(printf '%s' "$s" | openssl sha1 2>/dev/null | awk '{print $NF}' | cut -c 1-8)
+    else
+      h=$(python3 -c "import hashlib,sys; print(hashlib.sha1(sys.argv[1].encode()).hexdigest()[:8])" "$s" 2>/dev/null || echo "00000000")
+    fi
+    s="${s:0:23}-${h}"
   fi
   printf '%s\n' "${s:0:32}"
 }
@@ -272,13 +288,15 @@ case "$cmd" in
     fi
     if _real_herdr agent list 2>/dev/null | TARGET_NAME="$sess" python3 -c "
 import sys, json, os
+from lib_py.agents.sanitize import sanitize_herdr_agent_name
 tn = os.environ.get('TARGET_NAME', '')
+stn = sanitize_herdr_agent_name(tn)
 try:
     d = json.loads(sys.stdin.read())
     agents = d.get('result', {}).get('agents', [])
     for a in agents:
         an = a.get('name', '')
-        if an == tn or (len(tn) > 16 and an.startswith(tn[:14]) and an.endswith(tn[-12:])):
+        if an == tn or an == stn:
             sys.exit(0)
 except Exception:
     pass
@@ -507,7 +525,7 @@ except Exception:
         success=1
         break
       fi
-      if echo "$res" | grep -qiE "^usage:|unknown option|unknown flag"; then
+      if echo "$res" | grep -qiE "^usage:|unknown option|unknown flag|missing required|invalid_agent_name|^error:"; then
         break
       fi
       if [ "$i" -lt 2 ]; then

.agents/skills/lib_py/agents/sanitize.py

@@ -1,5 +1,4 @@
-# sanitize.py — Unified agent name sanitization contract for herdr 0.8.0 (E3 & E4)
-
+import hashlib
 import re
 
 def sanitize_herdr_agent_name(name: str) -> str:
@@ -8,7 +7,7 @@ def sanitize_herdr_agent_name(name: str) -> str:
     1. Convert to lowercase.
     2. Replace invalid characters ([^a-z0-9_-]) with '-'.
     3. Ensure starts with a lowercase letter [a-z], prefixing with 'x-' if needed.
-    4. Truncate to maximum 32 characters (16 + '-' + 15).
+    4. Truncate to maximum 32 characters using 8-char SHA-1 hash suffix (s[:23] + '-' + sha1[:8]).
     """
     if not name:
         return "agent"
@@ -23,8 +22,10 @@ def sanitize_herdr_agent_name(name: str) -> str:
     if not s or not s[0].isalpha():
         s = "x-" + s
     
-    # 4. Truncate to 32 chars if needed
+    # 4. Truncate to 32 chars if needed using collision-free SHA-1 hash suffix
     if len(s) > 32:
-        s = s[:16] + '-' + s[-15:]
+        h = hashlib.sha1(s.encode('utf-8')).hexdigest()[:8]
+        s = f"{s[:23]}-{h}"
     
     return s
+