[AZ-619] Phase A: build_pre_constructed seeds c13_fdr + clock

Adds airborne_bootstrap.build_pre_constructed(config) returning a
dict with the two foundational keys: a per-binary shared FdrClient
under "c13_fdr" (via make_fdr_client with the new
AIRBORNE_MAIN_PRODUCER_ID constant) and a fresh WallClock under
"clock". Phases B..F (AZ-620..AZ-624) extend this function
additively without breaking the AZ-619 contract.

The c13_fdr instance is identity-stable across calls (per the
make_fdr_client per-producer cache) so callers can call
build_pre_constructed twice and get the same FdrClient back -
AC-619.2.

Replay-mode override is unchanged: compose_root merges
replay_components over pre_constructed so the WallClock here is
replaced by TlogDerivedClock in replay binaries (existing
contract documented in compose_root's docstring).

Tests: 5 new unit tests under tests/unit/runtime_root/
test_az619_pre_constructed_phase_a.py, all passing. AZ-591 not
regressed (12/12 in the combined run).

Spec moved to _docs/02_tasks/done/.

Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/_autodev_state.md

@@ -6,10 +6,10 @@ step: 7
 name: Implement
 status: in_progress
 sub_step:
-  phase: 1
+  phase: 12
-  name: parse
+  name: archive
-  detail: "AZ-618 split into AZ-619..AZ-624 (subtasks of AZ-618; epic AZ-602). Next batch = AZ-619 (Phase A: c13_fdr + clock, 2pt). AZ-618 stays In Progress as umbrella; subtasks are To Do."
+  detail: "AZ-619 (Phase A) implemented + committed + tests green (12/12 incl. AZ-591 regression). Spec moved to done/. AZ-619 transitioned In Testing. Next batch = AZ-620 (Phase B: c6_descriptor_index + c6_tile_store, 3pt). Recommended session boundary here per 2026-05-18 lesson — fresh session picks up cleanly with AZ-620."
 retry_count: 0
 cycle: 1
 tracker: jira
-last_completed_batch: 89
+last_completed_batch: 90

src/gps_denied_onboard/runtime_root/airborne_bootstrap.py

@@ -51,8 +51,10 @@ from __future__ import annotations
 import logging
 import os
 from collections.abc import Mapping
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Final
 
+from gps_denied_onboard.clock.wall_clock import WallClock
+from gps_denied_onboard.fdr_client.client import make_fdr_client
 from gps_denied_onboard.runtime_root import register_strategy
 from gps_denied_onboard.runtime_root.matcher_factory import build_matcher_strategy
 from gps_denied_onboard.runtime_root.pose_factory import build_pose_estimator
@@ -66,12 +68,27 @@ if TYPE_CHECKING:
     from gps_denied_onboard.config import Config
 
 __all__ = [
+    "AIRBORNE_MAIN_PRODUCER_ID",
     "AIRBORNE_REQUIRED_PRE_CONSTRUCTED_KEYS",
     "AirborneBootstrapError",
+    "build_pre_constructed",
     "register_airborne_strategies",
 ]
 
 
+AIRBORNE_MAIN_PRODUCER_ID: Final[str] = "airborne_main"
+"""Producer ID for the per-binary shared FdrClient placed under
+``pre_constructed['c13_fdr']``.
+
+Per-component callers can still obtain their own FdrClient via
+``make_fdr_client(<their_slug>, config)`` — the cache in
+:mod:`gps_denied_onboard.fdr_client.client` ensures one instance per
+``producer_id``. The ``"airborne_main"`` instance is the one passed via
+``pre_constructed`` for the wrappers that accept ``fdr_client=`` as a
+kwarg.
+"""
+
+
 _LOG = logging.getLogger("gps_denied_onboard.runtime_root.airborne_bootstrap")
 
 
@@ -365,6 +382,30 @@ _AIRBORNE_REGISTRATIONS: tuple[
 )
 
 
+def build_pre_constructed(config: "Config") -> dict[str, Any]:
+    """Build the airborne ``pre_constructed`` dict for :func:`compose_root`.
+
+    AZ-619 (Phase A) lands the foundational keys ``c13_fdr`` and ``clock``.
+    Phases B..F (AZ-620..AZ-624) extend this function to populate the
+    remaining 10 keys in :data:`AIRBORNE_REQUIRED_PRE_CONSTRUCTED_KEYS`.
+
+    Returns a fresh dict on each call. The ``c13_fdr`` instance is cached
+    inside :func:`make_fdr_client` (per-producer cache) so two calls within
+    the same process return dicts where ``pre_constructed['c13_fdr']`` is
+    the SAME object — AC-619.2. ``clock`` is a fresh :class:`WallClock`
+    each call (stateless; the cache would be a no-op).
+
+    Replay-mode override: :func:`compose_root` merges ``replay_components``
+    over ``pre_constructed`` so the :class:`WallClock` here is replaced by
+    the replay branch's :class:`TlogDerivedClock`. That's intentional and
+    matches the contract in :func:`compose_root`'s docstring.
+    """
+    return {
+        "c13_fdr": make_fdr_client(AIRBORNE_MAIN_PRODUCER_ID, config),
+        "clock": WallClock(),
+    }
+
+
 def register_airborne_strategies() -> None:
     """Register every airborne (component, strategy) pair into ``_STRATEGY_REGISTRY``.
 

tests/unit/runtime_root/test_az619_pre_constructed_phase_a.py

@@ -0,0 +1,109 @@
+"""AZ-619 — Phase A of AZ-618: ``build_pre_constructed`` seeds c13_fdr + clock.
+
+Verifies the contract at
+``_docs/02_tasks/todo/AZ-619_pre_constructed_phase_a_c13_fdr_clock.md``:
+
+* AC-619.1: ``build_pre_constructed(default_config)`` returns a dict
+  containing keys ``c13_fdr`` (FdrClient instance) and ``clock``
+  (WallClock instance).
+* AC-619.2: invoking twice in the same process returns dicts where
+  ``c13_fdr`` is the SAME FdrClient instance (per ``make_fdr_client``
+  cache); ``clock`` may be a fresh WallClock each call.
+
+AC-619.3 (this file exists with the above tests) is satisfied by the
+existence of this module.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Iterator
+
+import pytest
+
+from gps_denied_onboard.clock.wall_clock import WallClock
+from gps_denied_onboard.config import Config
+from gps_denied_onboard.fdr_client import client as fdr_client_module
+from gps_denied_onboard.fdr_client.client import FdrClient
+from gps_denied_onboard.runtime_root.airborne_bootstrap import (
+    AIRBORNE_MAIN_PRODUCER_ID,
+    build_pre_constructed,
+)
+
+
+@pytest.fixture(autouse=True)
+def _isolated_fdr_cache() -> Iterator[None]:
+    # Arrange: every test starts with an empty FdrClient cache so AC-619.2's
+    # "same instance across calls" assertion is exercised against fresh state
+    # rather than stale cache from a prior test.
+    fdr_client_module._reset_for_tests()
+    yield
+    fdr_client_module._reset_for_tests()
+
+
+def test_ac_619_1_default_config_seeds_c13_fdr_and_clock() -> None:
+    # Arrange
+    config = Config()
+
+    # Act
+    pre_constructed = build_pre_constructed(config)
+
+    # Assert
+    assert "c13_fdr" in pre_constructed
+    assert "clock" in pre_constructed
+    assert isinstance(pre_constructed["c13_fdr"], FdrClient)
+    assert isinstance(pre_constructed["clock"], WallClock)
+
+
+def test_ac_619_1_c13_fdr_uses_airborne_main_producer_id() -> None:
+    # Arrange
+    config = Config()
+
+    # Act
+    pre_constructed = build_pre_constructed(config)
+
+    # Assert: the FdrClient is keyed under the documented producer ID so
+    # any per-component caller using the same ID gets the same instance.
+    assert pre_constructed["c13_fdr"].producer_id == AIRBORNE_MAIN_PRODUCER_ID
+
+
+def test_ac_619_2_c13_fdr_cached_across_calls() -> None:
+    # Arrange
+    config = Config()
+
+    # Act
+    first = build_pre_constructed(config)
+    second = build_pre_constructed(config)
+
+    # Assert: same FdrClient instance via make_fdr_client cache.
+    assert first["c13_fdr"] is second["c13_fdr"]
+
+
+def test_ac_619_2_clock_is_independent_instance_per_call() -> None:
+    # Arrange
+    config = Config()
+
+    # Act
+    first = build_pre_constructed(config)
+    second = build_pre_constructed(config)
+
+    # Assert: WallClock is stateless; identity-share is not contractual.
+    # Both must be valid WallClock instances. Identity may or may not match.
+    assert isinstance(first["clock"], WallClock)
+    assert isinstance(second["clock"], WallClock)
+
+
+def test_phase_a_only_seeds_two_keys() -> None:
+    """Phase A scope discipline: exactly the two documented keys.
+
+    Phases B..F (AZ-620..AZ-624) will add more keys; this test will be
+    relaxed at that point. For now it pins the AZ-619 contract precisely so
+    a regression that adds keys here without updating the spec is caught.
+    """
+    # Arrange
+    config = Config()
+
+    # Act
+    pre_constructed = build_pre_constructed(config)
+
+    # Assert
+    assert set(pre_constructed.keys()) == {"c13_fdr", "clock"}