[ACTP] add bootstrap-par-control command to PAR binary

[embeaken]

What does this PR do?

Adds privateactionrunner bootstrap-par-control, the command par-control runs at
startup. It makes Go the single configuration authority for split mode:

• loads the canonical Agent configuration (config.NewAgentParams +
  core.Bundle(core.WithSecrets())), so precedence, secrets, endpoint selection
  and Agent file-path resolution are the same ones the Go executor uses;
• reuses a valid persisted identity for the current host, self-enrolling and
  persisting otherwise;
• derives the PAR runtime configuration and emits it as a single
  PAR_CONTROL_CONFIG= prefixed JSON line on stdout.

When split mode is disabled it returns only the launch gate and log level and exits
successfully, without hostname lookup, identity access, enrollment, or the FIPS
check. When split mode is active it rejects FIPS mode rather than silently
consuming FIPS-transformed endpoints; a Gov site is not rejected on its own.

OPMS endpoint selection moves into a shared Config.OPMSEndpointURL helper used by
both the Go OPMS client and this command, so the Go and Rust runners cannot diverge
again — including under the fakeintake test switch.

Durations are emitted with explicit _milliseconds units. The payload carries the
runner private key and may carry proxy credentials, so it is never included in an
error.

This replaces the earlier ensure-enrollment command with no compatibility alias;
the enrollment helper and its tests moved rather than being rewritten. Rust no
longer loads or merges Agent configuration — see #54590.

Motivation

par-control previously loaded and merged Agent configuration itself, in Rust. That
duplicated the Go loader and let the two runners disagree; the OPMS endpoint had
already drifted once. Making Go authoritative removes roughly 1,640 lines of Rust
configuration code and the class of bug that goes with it.

Validation

• bazel test //cmd/privateactionrunner/subcommands/bootstrapparcontrol:bootstrapparcontrol_test
• bazel test //cmd/privateactionrunner/subcommands/rotateidentity:rotateidentity_test
• dda inv test --targets=./pkg/privateactionrunner/opms,./pkg/privateactionrunner/adapters/config
• Exercised against a registered staging runner end to end: bootstrap resolved the
  persisted identity and staging OPMS endpoint, and a UI-triggered
  script.testConnection produced a runPredefinedScript task that was verified,
  executed, and published successfully. The emitted payload never appeared in the
  control-plane log.

[dd-octo-sts]

Go Package Import Differences

Baseline: 296059f
Comparison: e24de5f

binary	os	arch	change
agent	linux	amd64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
agent	linux	arm64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
agent	windows	amd64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
agent	darwin	amd64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
agent	darwin	arm64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
agent	aix	ppc64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
iot-agent	linux	amd64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
iot-agent	linux	arm64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
heroku-agent	linux	amd64	+1, -0 +github.com/DataDog/datadog-agent/pkg/privateactionrunner/adapters/constants
privateactionrunner	linux	amd64	+2, -0 +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/bootstrapparcontrol +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/identity
privateactionrunner	linux	arm64	+2, -0 +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/bootstrapparcontrol +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/identity
privateactionrunner	windows	amd64	+2, -0 +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/bootstrapparcontrol +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/identity
privateactionrunner	darwin	amd64	+2, -0 +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/bootstrapparcontrol +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/identity
privateactionrunner	darwin	arm64	+2, -0 +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/bootstrapparcontrol +github.com/DataDog/datadog-agent/cmd/privateactionrunner/subcommands/identity

[datadog-prod-us1-4]

🎯 Code Coverage (details)
• Patch Coverage: 64.55%
• Overall Coverage: 52.63% (+0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: e24de5f | Docs | View more details | Give us feedback!}

[dd-octo-sts]

Files inventory check summary

File checks results against ancestor 296059ff:

Results for datadog-agent_7.84.0~devel.git.448.e24de5f.pipeline.132944334-1_amd64.deb:

No change detected

Results for datadog-iot-agent_7.84.0~devel.git.448.e24de5f.pipeline.132944334-1_amd64.deb:

No change detected

[dd-octo-sts]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor 296059f
📊 Static Quality Gates Dashboard
🔗 SQG Job

Successful checks

Info

	Quality gate	Change	Size (prev → curr → max)
✅	agent_deb_amd64	+24.16 KiB (0.00% increase, -0.69% of buffer)	761.181 → 761.204 → 764.600
✅	agent_msi	+25.0 KiB (0.00% increase, -0.18% of buffer)	647.835 → 647.859 → 661.050
✅	agent_rpm_amd64	+24.16 KiB (0.00% increase, -0.69% of buffer)	761.165 → 761.188 → 764.570
✅	agent_rpm_arm64	+20.16 KiB (0.00% increase, -76.93% of buffer)	737.104 → 737.124 → 737.130
✅	agent_suse_amd64	+24.16 KiB (0.00% increase, -0.69% of buffer)	761.165 → 761.188 → 764.570
✅	agent_suse_arm64	+20.16 KiB (0.00% increase, -76.93% of buffer)	737.104 → 737.124 → 737.130
✅	docker_agent_amd64	+24.16 KiB (0.00% increase, -6.22% of buffer)	819.760 → 819.784 → 820.140
✅	docker_agent_arm64	+20.15 KiB (0.00% increase, -11.06% of buffer)	820.712 → 820.732 → 820.890
✅	docker_agent_jmx_amd64	+24.16 KiB (0.00% increase, -9.75% of buffer)	1010.658 → 1010.682 → 1010.900
✅	docker_agent_jmx_arm64	+20.16 KiB (0.00% increase, -6.39% of buffer)	1000.262 → 1000.282 → 1000.570

23 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_deb_amd64_fips	713.931 MiB
✅	agent_heroku_amd64	312.896 MiB
✅	agent_rpm_amd64_fips	713.915 MiB
✅	agent_rpm_arm64_fips	693.134 MiB
✅	agent_suse_amd64_fips	713.915 MiB
✅	agent_suse_arm64_fips	693.134 MiB
✅	docker_cluster_agent_amd64	211.423 MiB
✅	docker_cluster_agent_arm64	224.458 MiB
✅	docker_cws_instrumentation_amd64	7.443 MiB
✅	docker_cws_instrumentation_arm64	6.877 MiB
✅	docker_dogstatsd_amd64	39.522 MiB
✅	docker_dogstatsd_arm64	37.623 MiB
✅	docker_host_profiler_amd64	306.843 MiB
✅	docker_host_profiler_arm64	318.121 MiB
✅	dogstatsd_deb_amd64	30.267 MiB
✅	dogstatsd_deb_arm64	28.294 MiB
✅	dogstatsd_rpm_amd64	30.267 MiB
✅	dogstatsd_suse_amd64	30.267 MiB
✅	iot_agent_deb_amd64	46.553 MiB
✅	iot_agent_deb_arm64	43.206 MiB
✅	iot_agent_deb_armhf	44.000 MiB
✅	iot_agent_rpm_amd64	46.554 MiB
✅	iot_agent_suse_amd64	46.553 MiB

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Job ID: f07c8c69-2ee1-48d4-b3b1-2cf8e699eb7c

Baseline: c45db9e
Comparison: e24de5f
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	dsd_uds_10mb_3k_timestamped_contexts_memory	memory utilization	+0.32	[+0.11, +0.53]	1	Logs
➖	quality_gate_metrics_logs	memory utilization	+0.17	[-0.06, +0.40]	1	Logs bounds checks dashboard
➖	quality_gate_private_action_runner	memory utilization	+0.16	[+0.04, +0.28]	1	Logs bounds checks dashboard
➖	quality_gate_security_no_fs_load	memory utilization	+0.14	[+0.05, +0.23]	1	Logs bounds checks dashboard
➖	quality_gate_idle	memory utilization	+0.02	[-0.03, +0.06]	1	Logs bounds checks dashboard
➖	quality_gate_idle_all_features	memory utilization	-0.04	[-0.08, -0.00]	1	Logs bounds checks dashboard
➖	quality_gate_security_mean_fs_load	memory utilization	-0.09	[-0.12, -0.05]	1	Logs bounds checks dashboard
➖	quality_gate_security_idle	memory utilization	-0.19	[-0.24, -0.15]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.61	[-1.48, +0.27]	1	Logs bounds checks dashboard
➖	dsd_uds_10mb_3k_timestamped_contexts_cpu	% cpu utilization	-0.86	[-1.10, -0.61]	1	Logs

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	observed_value	links
✅	quality_gate_idle	intake_connections	10/10	4 = 4	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	172.06MiB ≤ 178MiB	bounds checks dashboard
✅	quality_gate_idle	total_bytes_received	10/10	746.33KiB ≤ 819.20KiB	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	4 = 4	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	532.37MiB ≤ 538MiB	bounds checks dashboard
✅	quality_gate_idle_all_features	total_bytes_received	10/10	1.14MiB ≤ 1.25MiB	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	19 ≤ 40	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	213.00MiB ≤ 229MiB	bounds checks dashboard
✅	quality_gate_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_logs	total_bytes_received	10/10	263.51MiB ≤ 292MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	354.15 ≤ 2000	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	20 ≤ 40	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	405.99MiB ≤ 453MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_metrics_logs	total_bytes_received	10/10	0.94GiB ≤ 1.04GiB	bounds checks dashboard
✅	quality_gate_private_action_runner	memory_usage	10/10	71.99MiB ≤ 76MiB	bounds checks dashboard
✅	quality_gate_security_idle	cpu_usage	10/10	28.69 ≤ 100	bounds checks dashboard
✅	quality_gate_security_idle	memory_usage	10/10	326.99MiB ≤ 335MiB	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	cpu_usage	10/10	62.20 ≤ 200	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	memory_usage	10/10	305.35MiB ≤ 314MiB	bounds checks dashboard
✅	quality_gate_security_no_fs_load	cpu_usage	10/10	22.66 ≤ 100	bounds checks dashboard
✅	quality_gate_security_no_fs_load	memory_usage	10/10	310.12MiB ≤ 343MiB	bounds checks dashboard

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_security_no_fs_load, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_no_fs_load, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_private_action_runner, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_idle, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_security_mean_fs_load, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_mean_fs_load, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.