Function export_memory_digest

src/automation/memory_digest.rs:687–720

Projects the profile snapshot into one host channel, mirroring the `install_managed_skills` `(profile_root, target, output)` contract: native-overlay targets get a rule/skill file inside the plugin root, prompt-index targets get a marked block in the prompt file. When the snapshot is empty a short placeholder is exported instead (so refreshes after new facts can find and update the channel).

(
    profile_root: &Path,
    target: SkillInstallTarget,
    output: &Path,
)

/// snapshot is empty a short placeholder is exported instead (so refreshes
/// after new facts can find and update the channel).
pub fn export_memory_digest(
    profile_root: &Path,
    target: SkillInstallTarget,
    output: &Path,
) -> Result<MemoryDigestExportSummary> {
    if target == SkillInstallTarget::Hermes {
        return Err(hermes_host_owned_error());
    }
    if native_digest_superseded_by_host_injection(target) {
        return Err(native_digest_superseded_error(target));
    }
    let snapshot = load_memory_digest_snapshot(profile_root)?;
    let body = compose_digest_body(&snapshot, DEFAULT_DIGEST_CHAR_BUDGET);
    let fact_count = snapshot
        .projects
        .iter()
        .map(|section| section.lines.len())
        .sum();
    let body = body.unwrap_or_else(|| EMPTY_DIGEST_NOTE.to_string());

    let written = if target.is_native_overlay() {
        export_native_digest(target, output, &body)?
    } else {
        export_prompt_digest(output, &body)?;
        output.to_path_buf()
    };
    record_digest_target(profile_root, target, output)?;
    Ok(MemoryDigestExportSummary {
        target,
        output: written,
        fact_count,
        char_count: body.len(),
    })
}

/// Removes the digest artifact for one host channel and forgets the recorded
/// export target so refreshes stop re-creating it.