Add backfilled option to config registry

[BridgeAR]

The backfilled option showed some issue with the current state of
the supported-configurations.json. This is fixed by this PR by
adding setting backfilled to true as well as updating the generation
script to:

• lower case types
• use true and false as boolean
• use exact decimal values as defined in the macro

In addition, change DD_TRACE_RATE_LIMIT and
DD_TELEMETRY_EXTENDED_HEARTBEAT_INTERVAL decimal types to integers.

Some default values were changed from an empty string to nullptr, since
that seemed more suitable for these entries.

The script now also preserves the former implementation used.

[datadog-datadog-prod-us1]

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 90.89% (+0.00%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: da91ed8 | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}

[dmehala]

@BridgeAR I am trying to enforce conventional commit. Can you make sure to follow the convention when you're going to merge?

[pr-commenter]

Benchmarks

Benchmark execution time: 2026-04-05 19:36:27

Comparing candidate commit da91ed8 in PR branch BridgeAR/2026-04-02-add-backfilled with baseline commit b577e17 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 1 metrics, 0 unstable metrics.

Explanation

This is an A/B test comparing a candidate commit's performance against that of a baseline commit. Performance changes are noted in the tables below as:

• 🟩 = significantly better candidate vs. baseline
• 🟥 = significantly worse candidate vs. baseline

We compute a confidence interval (CI) over the relative difference of means between metrics from the candidate and baseline commits, considering the baseline as the reference.

If the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD), the change is considered significant.

Feel free to reach out to #apm-benchmarking-platform on Slack if you have any questions.

More details about the CI and significant changes

You can imagine this CI as a range of values that is likely to contain the true difference of means between the candidate and baseline commits.

CIs of the difference of means are often centered around 0%, because often changes are not that big:

---------------------------------(------|---^--------)-------------------------------->
                              -0.6%    0%  0.3%     +1.2%
                                 |          |        |
         lower bound of the CI --'          |        |
sample mean (center of the CI) -------------'        |
         upper bound of the CI ----------------------'

As described above, a change is considered significant if the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD).

For instance, for an execution time metric, this confidence interval indicates a significantly worse performance:

----------------------------------------|---------|---(---------^---------)---------->
                                       0%        1%  1.3%      2.2%      3.1%
                                                  |   |         |         |
       significant impact threshold --------------'   |         |         |
                      lower bound of CI --------------'         |         |
       sample mean (center of the CI) --------------------------'         |
                      upper bound of CI ----------------------------------'