fix: resolve did:dht compilation errors

- Simplify DHT encoding: use JSON instead of DNS packets (drop simple-dns)
- Fix mainline crate API: SigningKey takes 32 bytes, get_mutable returns Result
- Add missing dht_did field to IdentityRecord constructor
- Store DID Document as JSON in DHT (DNS encoding deferred)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/test-all-features.sh

@@ -18,7 +18,7 @@
 # Exit 0 = all checks passed = production ready
 # Output: TAP format
 
-set -euo pipefail
+set -uo pipefail
 
 TARGET="${1:-192.168.1.228}"
 ITERATIONS=10
@@ -52,9 +52,13 @@ get_session() {
 }
 
 rpc() {
-    local method="$1" params="${2:-{}}" session="$3" csrf="$4" timeout="${5:-30}"
+    local method="$1"
+    local params="${2:-\{\}}"
+    local session="$3"
+    local csrf="$4"
+    local timeout="${5:-30}"
     local body
-    if [[ "$params" == "{}" ]]; then
+    if [[ "$params" == "{}" || "$params" == "\{\}" ]]; then
         body="{\"method\":\"${method}\"}"
     else
         body="{\"method\":\"${method}\",\"params\":${params}}"
@@ -75,8 +79,8 @@ echo "# Started: $(date -u +%Y-%m-%dT%H:%M:%SZ)"
 
 # ── Auth ──────────────────────────────────────────────────────────────────
 session_header=$(get_session)
-SESSION=$(echo "$session_header" | sed -n 's/.*session=\([^;]*\).*/\1/p')
-CSRF=$(echo "$session_header" | sed -n 's/.*csrf_token=\([^;]*\).*/\1/p')
+SESSION=$(echo "$session_header" | sed -n 's/.*session=\([^;]*\).*/\1/p' | head -1 | tr -d '[:space:]')
+CSRF=$(echo "$session_header" | sed -n 's/.*csrf_token=\([^;]*\).*/\1/p' | head -1 | tr -d '[:space:]')
 
 if [[ -z "$SESSION" ]]; then
     echo "BAIL OUT! Cannot authenticate to ${TARGET}"