fix(plugins): stamp surface identity at record time, not send time

Six defects in 0.3.x plugin telemetry. Defects 1, 2 and 6 were not three bugs:
they were one spool protocol getting three properties wrong.

Identity was decided by the wrong process. `harness` was stamped in record(),
correctly, but `source` was read from a module global in flush() — so whichever
process drained the spool named every event in it. Two processes never call
init(): mcp_server.py, and the detached `python3 telemetry.py` sender that
spawn_flush() starts. record() now stamps source beside harness, and the build
generates core/_harness_id.py per host so identity resolves with no init() call
at all. That also unifies two defaults that disagreed (`<host>_plugin` vs
`MEM0_<HOST>_PLUGIN`), which could yield three source values for one plugin.

Ownership was inferred, not held. Path.replace is os.rename, which preserves
mtime, so a claim made after a quiet minute inherited the spool's age and was
stealable the instant it existed. Claims are touched on creation and the
per-batch rewrite doubles as a lease heartbeat.

Progress was not durable. flush() returned on the first failed batch without
truncating, so the retry re-posted from index 0 — 150 events delivered 250
times. It now rewrites the claim with the unsent remainder after every batch,
bounding a crash to one repeated batch, and each event carries a uuid.

Parked batches starved. They were only reachable when no spool existed, and
because sessions keep recording there usually was one, so a batch parked by a
failed send waited until the 7-day expiry deleted it unsent — despite its own
presence being what starts the sender. flush() drains them in the same run, and
expiry now applies only after a genuine retry has failed.

code.install counted upgrades and repeat sessions. is_first_run() read the
identity file, which only a successful flush writes, so an offline user recorded
an install every session forever. A dedicated install-state.json is claimed
atomically at record time; a non-empty data directory reads as an upgrade.

The docs called this anonymous. Every event carries the account email, and the
hashes were unsalted SHA-256 over a git remote URL or an absolute path
containing the username. READMEs, the module docstring and a new docs section
now say what the code does, and repo/session digests are salted per install.

A cached email outlived an API key change. It is now re-resolved when the key's
fingerprint differs, and $identify aliases anonymous->email only — aliasing one
account to another merges person profiles irreversibly.

All six shipped green because the shared core's only tests lived under one host,
behind a conftest that calls init() at import. Core behaviour was never
exercised uninitialised. Adds agent-plugin-core/tests with no init, including
subprocess tests and coverage for the portable plugin, which has no flush worker
and would pass a native-only test vacuously.

Also puts the three surface headers on the SDKs, CLIs and integrations, and
corrects a README claiming ZAPIER/STRANDS were already in the platform allowlist.

Verified: 59 core tests, 203 claude-code, 11 cursor, 5 codex, 2 kimi, 6
antigravity. ruff and compileall clean. --check clean for all six hosts.
TypeScript changes are not typechecked locally (deps not installed).

Claude-Session: https://claude.ai/code/session_01C7tEmH86HAr7GoAAKCEHZb

integrations/agent-plugin-core/tests/test_spool_delivery.py

@@ -0,0 +1,164 @@
+"""Delivery semantics of the telemetry spool: no duplicates, no starvation.
+
+These run against a built host's core in-process (not a subprocess) because they
+need to inject failures into ``_post``. The identity tests next door cover the
+uninitialised-process case that needs a real interpreter.
+"""
+
+from __future__ import annotations
+
+import importlib
+import json
+import os
+import sys
+import time
+from pathlib import Path
+
+import pytest
+
+CORE_ROOT = Path(__file__).resolve().parents[1]
+REPOSITORY_ROOT = CORE_ROOT.parents[1]
+HOST_CORE = REPOSITORY_ROOT / "integrations" / "claude-code-plugin" / "core"
+
+pytestmark = pytest.mark.skipif(not HOST_CORE.exists(), reason="claude-code-plugin is not built")
+
+
+@pytest.fixture()
+def telemetry(tmp_path, monkeypatch):
+    monkeypatch.setenv("MEM0_CODE_DATA_DIR", str(tmp_path / "data"))
+    monkeypatch.syspath_prepend(str(HOST_CORE))
+    for name in ("telemetry", "memory_core", "_harness_id"):
+        sys.modules.pop(name, None)
+    module = importlib.import_module("telemetry")
+    monkeypatch.setattr(module, "resolve_distinct_id", lambda: ("tester@example.com", ""))
+    yield module
+    for name in ("telemetry", "memory_core", "_harness_id"):
+        sys.modules.pop(name, None)
+
+
+def _delivered(payloads):
+    return [event for payload in payloads if "batch" in payload for event in payload["batch"]]
+
+
+def test_a_partial_failure_does_not_redeliver_what_already_arrived(telemetry):
+    """Defect 2a: flush kept the whole claim on failure and retried from the top.
+
+    150 events across two batches, the second failing, previously delivered 250.
+    """
+    for index in range(150):
+        telemetry.record("search", index=index)
+
+    sent: list[dict] = []
+    calls = {"n": 0}
+
+    def flaky(payload, url):
+        calls["n"] += 1
+        if calls["n"] == 2:  # second batch fails
+            return False
+        sent.append(payload)
+        return True
+
+    telemetry._post = flaky
+    telemetry.flush()
+
+    telemetry._post = lambda payload, url: sent.append(payload) or True
+    telemetry.flush()
+
+    events = _delivered(sent)
+    assert len(events) == 150
+    assert len({event["uuid"] for event in events}) == 150
+
+
+def test_a_fresh_claim_is_not_immediately_stealable(telemetry):
+    """Defect 2b: rename preserves mtime, so a claim inherited the spool's age.
+
+    With the last write older than the stale threshold, a claim made now looked
+    abandoned the instant it existed and a second sender took it over.
+    """
+    telemetry.record("search")
+    spool = telemetry._spool_path()
+    old = time.time() - (telemetry.CLAIM_STALE_SECONDS + 60)
+    os.utime(spool, (old, old))
+
+    first = telemetry._claim_spool()
+    assert first is not None
+
+    # A second sender starting right now must find nothing to take.
+    assert telemetry._claim_parked(first.parent) is None
+
+
+def test_a_parked_batch_is_drained_behind_the_live_spool(telemetry):
+    """Defect 6: parked claims were only reachable when no spool existed.
+
+    Because sessions keep recording there usually was one, so a batch parked by
+    a failed send waited until the 7-day expiry deleted it unsent — even though
+    its own presence is what starts the sender.
+    """
+    telemetry.record("parked")
+    telemetry._post = lambda payload, url: False
+    telemetry.flush()
+
+    parked = list(telemetry.memory_core.data_dir().glob("telemetry-*.sending"))
+    assert len(parked) == 1
+    old = time.time() - (telemetry.CLAIM_STALE_SECONDS + 60)
+    os.utime(parked[0], (old, old))
+
+    telemetry.record("fresh")
+    sent: list[dict] = []
+    telemetry._post = lambda payload, url: sent.append(payload) or True
+    telemetry.flush()
+
+    names = {event["event"] for event in _delivered(sent)}
+    assert names == {"code.parked", "code.fresh"}
+
+
+def test_an_untried_batch_is_not_expired_by_age_alone(telemetry):
+    """Expiry should discard what failed, not what never got a turn."""
+    telemetry.record("parked")
+    telemetry._post = lambda payload, url: False
+    telemetry.flush()
+
+    parked = list(telemetry.memory_core.data_dir().glob("telemetry-*.sending"))
+    assert len(parked) == 1
+    ancient = time.time() - (telemetry.CLAIM_EXPIRY_SECONDS + 60)
+    os.utime(parked[0], (ancient, ancient))
+
+    sent: list[dict] = []
+    telemetry._post = lambda payload, url: sent.append(payload) or True
+    telemetry.flush()
+
+    assert [event["event"] for event in _delivered(sent)] == ["code.parked"]
+
+
+def test_progress_is_recorded_after_every_batch(telemetry):
+    """A crash repeats at most one batch, not the whole file."""
+    for index in range(250):
+        telemetry.record("search", index=index)
+
+    calls = {"n": 0}
+
+    def die_after_two(payload, url):
+        calls["n"] += 1
+        if calls["n"] > 2:
+            return False
+        return True
+
+    telemetry._post = die_after_two
+    telemetry.flush()
+
+    parked = list(telemetry.memory_core.data_dir().glob("telemetry-*.sending"))
+    assert len(parked) == 1
+    remaining = parked[0].read_text(encoding="utf-8").strip().splitlines()
+    # Two batches of 100 landed; only the last 50 should still be pending.
+    assert len(remaining) == 50
+    assert json.loads(remaining[0])["properties"]["index"] == 200
+
+
+def test_the_heartbeat_stays_well_inside_the_lease(telemetry):
+    """The claim rewrite doubles as the lease heartbeat.
+
+    _post makes a single attempt with SEND_TIMEOUT and no retry, so a heartbeat
+    lands at least that often. If a retry loop is ever added to _post, this is
+    the assertion that catches a sender losing its claim mid-flight.
+    """
+    assert telemetry.SEND_TIMEOUT * 4 < telemetry.CLAIM_STALE_SECONDS