fix: sync error_handler fallback, Alpine APK repair, retry limit

error_handler.func:
- Sync fallback explain_exit_code() with api.func: add 25+ codes that
  were missing (curl 16/18/24/26/27/32-34/36/39/44-48/51/52/55/57/59/
  61/63/79/92/95, signals 125/129/131/132/144/146, npm 239, code 3/8)
- Ensures consistent error descriptions even when api.func isn't loaded

build.func:
- Alpine APK repair: detect var_os=alpine and run 'apk fix && apk
  cache clean && apk update' instead of apt-get/dpkg commands
- Show 'Repair APK state' instead of 'APT/DPKG' in menu for Alpine
- Retry safety counter: OOM x2 retry limited to max 2 attempts
  (prevents infinite RAM doubling via RECOVERY_ATTEMPT env var)
- Show attempt count in rebuild summary

misc/error_handler.func

@@ -37,21 +37,47 @@ if ! declare -f explain_exit_code &>/dev/null; then
     case "$code" in
     1) echo "General error / Operation not permitted" ;;
     2) echo "Misuse of shell builtins (e.g. syntax error)" ;;
+    3) echo "General syntax or argument error" ;;
     10) echo "Docker / privileged mode required (unsupported environment)" ;;
     4) echo "curl: Feature not supported or protocol error" ;;
     5) echo "curl: Could not resolve proxy" ;;
     6) echo "curl: DNS resolution failed (could not resolve host)" ;;
     7) echo "curl: Failed to connect (network unreachable / host down)" ;;
-    8) echo "curl: FTP server reply error" ;;
+    8) echo "curl: Server reply error (FTP/SFTP or apk untrusted key)" ;;
+    16) echo "curl: HTTP/2 framing layer error" ;;
+    18) echo "curl: Partial file (transfer not completed)" ;;
     22) echo "curl: HTTP error returned (404, 429, 500+)" ;;
     23) echo "curl: Write error (disk full or permissions)" ;;
+    24) echo "curl: Write to local file failed" ;;
     25) echo "curl: Upload failed" ;;
+    26) echo "curl: Read error on local file (I/O)" ;;
+    27) echo "curl: Out of memory (memory allocation failed)" ;;
     28) echo "curl: Operation timeout (network slow or server not responding)" ;;
     30) echo "curl: FTP port command failed" ;;
+    32) echo "curl: FTP SIZE command failed" ;;
+    33) echo "curl: HTTP range error" ;;
+    34) echo "curl: HTTP post error" ;;
     35) echo "curl: SSL/TLS handshake failed (certificate error)" ;;
+    36) echo "curl: FTP bad download resume" ;;
+    39) echo "curl: LDAP search failed" ;;
+    44) echo "curl: Internal error (bad function call order)" ;;
+    45) echo "curl: Interface error (failed to bind to specified interface)" ;;
+    46) echo "curl: Bad password entered" ;;
+    47) echo "curl: Too many redirects" ;;
+    48) echo "curl: Unknown command line option specified" ;;
+    51) echo "curl: SSL peer certificate or SSH host key verification failed" ;;
+    52) echo "curl: Empty reply from server (got nothing)" ;;
+    55) echo "curl: Failed sending network data" ;;
     56) echo "curl: Receive error (connection reset by peer)" ;;
+    57) echo "curl: Unrecoverable poll/select error (system I/O failure)" ;;
+    59) echo "curl: Couldn't use specified SSL cipher" ;;
+    61) echo "curl: Bad/unrecognized transfer encoding" ;;
+    63) echo "curl: Maximum file size exceeded" ;;
     75) echo "Temporary failure (retry later)" ;;
     78) echo "curl: Remote file not found (404 on FTP/file)" ;;
+    79) echo "curl: SSH session error (key exchange/auth failed)" ;;
+    92) echo "curl: HTTP/2 stream error (protocol violation)" ;;
+    95) echo "curl: HTTP/3 layer error" ;;
     64) echo "Usage error (wrong arguments)" ;;
     65) echo "Data format error (bad input data)" ;;
     66) echo "Input file not found (cannot open input)" ;;
@@ -69,15 +95,21 @@ if ! declare -f explain_exit_code &>/dev/null; then
     101) echo "APT: Configuration error (bad sources.list, malformed config)" ;;
     102) echo "APT: Lock held by another process (dpkg/apt still running)" ;;
     124) echo "Command timed out (timeout command)" ;;
+    125) echo "Command failed to start (Docker daemon or execution error)" ;;
     126) echo "Command invoked cannot execute (permission problem?)" ;;
     127) echo "Command not found" ;;
     128) echo "Invalid argument to exit" ;;
-    130) echo "Terminated by Ctrl+C (SIGINT)" ;;
+    129) echo "Killed by SIGHUP (terminal closed / hangup)" ;;
+    130) echo "Aborted by user (SIGINT)" ;;
+    131) echo "Killed by SIGQUIT (core dumped)" ;;
+    132) echo "Killed by SIGILL (illegal CPU instruction)" ;;
     134) echo "Process aborted (SIGABRT - possibly Node.js heap overflow)" ;;
     137) echo "Killed (SIGKILL / Out of memory?)" ;;
     139) echo "Segmentation fault (core dumped)" ;;
     141) echo "Broken pipe (SIGPIPE - output closed prematurely)" ;;
     143) echo "Terminated (SIGTERM)" ;;
+    144) echo "Killed by signal 16 (SIGUSR1 / SIGSTKFLT)" ;;
+    146) echo "Killed by signal 18 (SIGTSTP)" ;;
     150) echo "Systemd: Service failed to start" ;;
     151) echo "Systemd: Service unit not found" ;;
     152) echo "Permission denied (EACCES)" ;;
@@ -123,6 +155,7 @@ if ! declare -f explain_exit_code &>/dev/null; then
     224) echo "Proxmox: PBS storage is for backups only" ;;
     225) echo "Proxmox: No template available for OS/Version" ;;
     231) echo "Proxmox: LXC stack upgrade failed" ;;
+    239) echo "npm/Node.js: Unexpected runtime error or dependency failure" ;;
     243) echo "Node.js: Out of memory (JavaScript heap out of memory)" ;;
     245) echo "Node.js: Invalid command-line option" ;;
     246) echo "Node.js: Internal JavaScript Parse Error" ;;