feat(vector): compile ordered signal mutations

[vntrevx]

Implements roadmap M21-01.

• Adds the versioned signal-program-v1 schema, static compiler, validator, Python reference executor, CLI, and modular documentation.
• Preserves Freqtrade entry-before-exit, masked/full-column assignment, read-after-write, nullable Boolean mask, and source-order last-write semantics without Signal-number runtime branches.
• Captures a pinned Freqtrade 2026.5.1 advise_entry/advise_exit oracle and fixes exact numeric-one signal activation plus wrapper initialization/legacy rename behavior in the current vector lane.
• Keeps tag generation explicitly fail-closed for M21-02 and records latest X7 self.config as the next typed lowering boundary; no Full Native latest-X7 claim.

Validation:

• Python: 786 passed
• Future compatibility: 143 passed
• Rust: 143 sim-core + 66 vector-core + 3 vector-io passed
• Ruff, basedpyright, rustfmt, workspace Clippy -D warnings passed
• Spot and Futures full fixtures: trade surface and full-state exact

Risk: signal transport semantics changed from nonzero to the exact Freqtrade comparison value == 1. Existing X7 emits only 0/1; focused Python and Rust boundary tests cover 2, -1, string 1, NaN, and null.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 9b25f24e8e

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Preserve boolean signals in a numeric form

When a strategy assigns boolean signals (for example dataframe['enter_long'] = dataframe['cond'], which Freqtrade/Python treats as enabled because True == 1), this now preserves the boolean dtype into nfi_exec_enter_long. The Rust vector reader still routes signal columns through required_number, which rejects Arrow Boolean, so valid boolean signal strategies will fail in the native lane after the vector worker writes the Feather artifact; normalize boolean signal columns to a numeric 0/1 representation before serialization while still leaving non-one numeric values unpromoted.

AGENTS.md reference: AGENTS.md:L30-L31

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Account for helper-owned signal writes

If populate_entry_trend or populate_exit_trend delegates its final DataFrame mutation to a helper, _SignalCompiler records that helper's frame-write in final_mutations, but validation skips every helper-owned write here and recomputes signal_outputs only from entrypoint-owned nodes. As a result, a strategy such as dataframe = self.set_entry(dataframe); return dataframe, where set_entry writes enter_long, makes compile_signal_program() reject its own compiled program with final output inventory differs instead of producing the ordered mutation program.

Useful? React with 👍 / 👎.