feat(tabs): live tab resync + adopt-by-targetId + open --reuse-tab (#21)

Multi-session over one relayed Chrome had a tab-identity fracture: each daemon
discovered targets ONCE at connect and assigned its own t<N> indices, so a tab
filled in session A was unreachable from session B — B saw a disjoint/blank set
and rebinding via 'open' piled up duplicate tabs. A stranded, still-filled tab
could not be finished from any other session.

- 'tab list' now re-syncs the live target set on every call: adopts tabs other
  sessions opened (or that re-attached after a cross-process nav), drops gone
  ones (clears phantom rows), and refreshes url/title from each live tab via
  Target.getTargetInfo (the relay only stamps target_info on attach, so it goes
  stale/blank after navigation — which made rows indistinguishable).
- 'tab list --full' now prints each tab's stable CDP targetId. Unlike t<N>
  (per-session, reassigned each connect), targetId is stable across every session
  on the relayed Chrome.
- 'tab <targetId>' adopts a specific pre-existing tab — including another
  session's — WITHOUT reloading, so a half-filled form survives. handle_tab_switch
  resyncs first, then resolves a raw targetId before falling back to t<N>/label.
- 'open <url> --reuse-tab' (alias --reuse) switches to an existing tab already on
  that URL (matched by origin+path, ignoring volatile query/fragment) instead of
  spawning a duplicate.

Verified live over the extension relay: a fresh session's 'tab list --full' lists
the user's real tabs with correct titles + full URLs + targetIds, and
'tab <targetId>' lands on and reads the exact stranded Rakuten account-recovery
form from the report. Unit tests cover URL normalization + --reuse-tab parsing;
full suite green. Docs: --help Tabs section + core skill multi-session guidance.

cli/src/native/actions.rs

@@ -2531,6 +2531,20 @@ async fn handle_navigate(cmd: &Value, state: &mut DaemonState) -> Result<Value,
     state.ref_map.clear();
     state.iframe_sessions.clear();
     state.active_frame_id = None;
+
+    // `--reuse-tab`: if a tab already shows this URL (same origin+path), switch
+    // to it instead of navigating — preserves any in-page state and stops
+    // re-`open` from piling up duplicate tabs on rebind (issue #21).
+    if cmd
+        .get("reuseTab")
+        .and_then(|v| v.as_bool())
+        .unwrap_or(false)
+    {
+        if let Ok(Some(switched)) = mgr.reuse_tab_for_url(url).await {
+            return Ok(switched);
+        }
+    }
+
     let result = mgr.navigate(url, wait_until).await?;
     // Adaptive humanize: sample the freshly loaded page for known behavioural
     // anti-bot vendors and escalate this session to Human if any are present.
@@ -4355,8 +4369,12 @@ async fn handle_keyboard(cmd: &Value, state: &DaemonState) -> Result<Value, Stri
 // Phase 5 handlers
 // ---------------------------------------------------------------------------
 
-async fn handle_tab_list(cmd: &Value, state: &DaemonState) -> Result<Value, String> {
-    let mgr = state.browser.as_ref().ok_or("Browser not launched")?;
+async fn handle_tab_list(cmd: &Value, state: &mut DaemonState) -> Result<Value, String> {
+    let mgr = state.browser.as_mut().ok_or("Browser not launched")?;
+    // Re-sync with the live browser so the list reflects tabs opened by other
+    // sessions or re-attached after a cross-process nav, and drops gone ones
+    // (issue #21). Best-effort: a stale list still beats erroring the command.
+    mgr.resync_targets().await.ok();
     let tabs = mgr.tab_list();
     // Echo `full` so the formatter prints untruncated URLs (issue #19).
     if cmd.get("full").and_then(|v| v.as_bool()).unwrap_or(false) {
@@ -4394,9 +4412,20 @@ async fn handle_tab_switch(cmd: &Value, state: &mut DaemonState) -> Result<Value
     let tab_ref_str = cmd
         .get("tabId")
         .and_then(|v| v.as_str())
-        .ok_or("Missing 'tabId' parameter (expected `t<N>` or a label)")?;
-    let tab_ref = super::browser::TabRef::parse(tab_ref_str)?;
-    let tab_id = mgr.resolve_tab_ref(&tab_ref)?;
+        .ok_or("Missing 'tabId' parameter (expected `t<N>`, a label, or a targetId)")?;
+    // Re-sync first so a tab opened by another session, or one that re-attached
+    // after a cross-process nav, is adoptable from here (issue #21).
+    mgr.resync_targets().await.ok();
+    // A CDP `targetId` (shown in `tab list`) is stable across sessions, so accept
+    // it directly for adopting a specific pre-existing tab — falling back to the
+    // per-session `t<N>` / label form.
+    let tab_id = match mgr.tab_id_for_target(tab_ref_str) {
+        Some(id) => id,
+        None => {
+            let tab_ref = super::browser::TabRef::parse(tab_ref_str)?;
+            mgr.resolve_tab_ref(&tab_ref)?
+        }
+    };
     state.ref_map.clear();
     state.iframe_sessions.clear();
     state.active_frame_id = None;