fix(migrate-v2): correct JID parsing, Discord guildId lookup, silent failures

- shared.ts: parseJid now recognizes raw Baileys WhatsApp JIDs
  (`<id>@s.whatsapp.net`, `@g.us`, etc.); v2PlatformId returns the raw
  JID for whatsapp to match what the runtime adapter emits. Without this,
  every WhatsApp group in a v1 install was silently skipped.

- discord-resolver.ts: new helper that uses DISCORD_BOT_TOKEN to look up
  channelId → guildId via the Discord API, since v1 stored only the
  channel id but v2 needs `discord:<guildId>:<channelId>`. Best-effort:
  on missing/invalid token or network error, returns empty resolver and
  the affected groups are skipped with the reason surfaced per channel.

- db.ts, tasks.ts: route Discord groups through the resolver; other
  channels go through v2PlatformId unchanged. Resolver only built when
  at least one Discord group exists, so non-Discord installs incur no
  network.

- db.ts: when every v1 group is skipped, exit non-zero with a FAIL line
  instead of `OK:groups=N,...,skipped=N`, so the wrapper doesn't hide
  total failure under a successful-looking summary.

- migrate-v2.sh: run_step now surfaces ERROR: lines from successful
  steps (with count + first 3 + raw log path); phase 2c install loop
  populates STEP_RESULTS so install failures show in handoff.json
  instead of silently passing.

- sessions.ts: copyTree skips dangling symlinks (e.g. v1's
  `.claude/debug/latest`) instead of crashing the entire step.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

migrate-v2.sh

@@ -259,6 +259,18 @@ run_step() {
     step_ok "$label $(dim "$result")"
     log "$name: $result"
     STEP_RESULTS[$name]="success"
+    # Surface partial errors (rows skipped due to parse/lookup failures)
+    # even when the step exited successfully — they're easy to miss in the
+    # raw log and have caused silent migrations before.
+    if grep -q '^ERROR:' "$raw" 2>/dev/null; then
+      local err_count
+      err_count=$(grep -c '^ERROR:' "$raw")
+      echo "  $(dim "${err_count} error(s) reported — see $raw")"
+      grep '^ERROR:' "$raw" | head -3 | while IFS= read -r line; do
+        echo "  $(dim "$line")"
+      done
+      log "$name: ${err_count} non-fatal errors"
+    fi
   elif grep -q '^SKIPPED:' "$raw" 2>/dev/null; then
     local reason
     reason=$(grep '^SKIPPED:' "$raw" | head -1 | sed 's/^SKIPPED://')
@@ -340,14 +352,17 @@ else
   # 2c. Install channel code
   for ch in "${SELECTED_CHANNELS[@]}"; do
     INSTALL_SCRIPT="setup/install-${ch}.sh"
+    STEP_NAME="2c-install-${ch}"
     if [ -f "$INSTALL_SCRIPT" ]; then
-      STEP_LOG="$STEPS_DIR/2c-install-${ch}.log"
+      STEP_LOG="$STEPS_DIR/${STEP_NAME}.log"
       if bash "$INSTALL_SCRIPT" > "$STEP_LOG" 2>&1; then
         STATUS_LINE=$(grep '^STATUS:' "$STEP_LOG" | head -1 | sed 's/^STATUS: *//')
         if [ "$STATUS_LINE" = "already-installed" ]; then
           step_skip "Install $ch $(dim "(already installed)")"
+          STEP_RESULTS[$STEP_NAME]="skipped"
         else
           step_ok "Install $ch"
+          STEP_RESULTS[$STEP_NAME]="success"
         fi
         log "install-$ch: $STATUS_LINE"
       else
@@ -356,9 +371,12 @@ else
           echo "  $(dim "$line")"
         done
         log "install-$ch: FAILED (see $STEP_LOG)"
+        STEP_RESULTS[$STEP_NAME]="failed"
       fi
     else
       step_skip "Install $ch $(dim "(no install script)")"
+      log "install-$ch: no install script"
+      STEP_RESULTS[$STEP_NAME]="failed"
     fi
   done
 fi