feat: Pipeline Settings M1 — per-step model picker, system instructions, agent prompts (v0.23.0)

Adds a new 'Pipeline' wp-admin submenu page (prautoblogger-pipeline) with a
step rail covering all LLM stages: Research, Analysis, Writer, Editorial, Image.

Per-step panels surface:
- The existing PRAutoBlogger_OpenRouter_Model_Field picker (no new dropdown) with
  stage-accurate cost-preview for each step.
- System-instructions editor + agent-prompt editor(s) bound to the versioned
  prompt registry. Saving creates a new immutable version; reset-to-default
  available; active version number shown per panel.
- Step params read from PRAutoBlogger_Prompt_Registry::defs() (read-only in M1).

Writer panel marks inactive sub-stage prompts based on current pipeline mode.

No existing Settings sections changed — both surfaces edit the same wp_options
and prompts table. Decomposition of AI Models / Content / Sources tabs is M2.

get_stages_for_setting() extended: prautoblogger_research_model → [research,
llm_research] and prautoblogger_image_model → [image_a, image_b] for
cost-preview accuracy.

New files (4 classes + 1 CSS + 1 JS + 2 templates, all <=300 lines):
  includes/admin/class-pipeline-settings-page.php
  includes/admin/class-pipeline-settings-renderer.php
  includes/admin/class-pipeline-settings-save-handler.php
  includes/admin/class-pipeline-settings-step-map.php
  assets/css/pipeline-settings.css
  assets/js/pipeline-settings.js
  templates/admin/pipeline-settings-page.php
  templates/admin/pipeline-settings-prompt-panel.php

Modified:
  includes/admin/fields/class-open-router-model-field.php
  includes/class-prautoblogger.php
  prautoblogger.php (v0.23.0)
  ARCHITECTURE.md / INFORMATION-ARCHITECTURE.md / CHANGELOG.md

No new wp_options; uninstall unchanged.

Agent-Session: pipeline-settings-m1

templates/admin/pipeline-settings-page.php

@@ -0,0 +1,194 @@
+<?php
+/**
+ * Pipeline Settings page template.
+ *
+ * Variables injected by PRAutoBlogger_Pipeline_Settings_Renderer::render():
+ *   array   $view['steps']        — ordered step definitions from Step_Map.
+ *   array   $view['active_step']  — the currently selected step definition.
+ *   array   $view['save_result']  — {status, message} from the save handler.
+ *   string  $view['nonce_field']  — nonce field name.
+ *   string  $view['nonce_action'] — nonce action string.
+ *   string  $view['page_slug']    — pipeline page slug.
+ *   array   $view['step_data']    — assembled view data for the active step.
+ *
+ * Prompt panels are rendered via the pipeline-settings-prompt-panel.php partial.
+ *
+ * @see admin/class-pipeline-settings-renderer.php — Provides $view.
+ * @see admin/class-pipeline-settings-page.php     — Includes this template.
+ * @see templates/admin/pipeline-settings-prompt-panel.php — Prompt editor partial.
+ */
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+$steps        = $view['steps'];
+$active_step  = $view['active_step'];
+$save_result  = $view['save_result'];
+$nonce_field  = $view['nonce_field'];
+$nonce_action = $view['nonce_action'];
+$page_slug    = $view['page_slug'];
+$step_data    = $view['step_data'];
+
+$base_url = admin_url( 'admin.php?page=' . rawurlencode( $page_slug ) );
+
+$cost_reporter = new PRAutoBlogger_Cost_Reporter();
+$monthly_spend = $cost_reporter->get_monthly_spend();
+$budget        = (float) get_option( 'prautoblogger_monthly_budget_usd', 50.00 );
+?>
+<div class="wrap ab-wrap pab-pipeline-wrap">
+
+	<div class="ab-header">
+		<div class="ab-header-left">
+			<span class="dashicons dashicons-networking ab-header-icon"></span>
+			<div>
+				<h1 class="ab-header-title"><?php esc_html_e( 'Pipeline Settings', 'prautoblogger' ); ?></h1>
+				<span class="ab-header-version">v<?php echo esc_html( PRAUTOBLOGGER_VERSION ); ?></span>
+			</div>
+		</div>
+		<div class="ab-header-actions">
+			<a href="<?php echo esc_url( admin_url( 'admin.php?page=prautoblogger-settings' ) ); ?>" class="ab-btn ab-btn-outline">
+				<?php esc_html_e( '← All Settings', 'prautoblogger' ); ?>
+			</a>
+		</div>
+	</div>
+
+	<div class="ab-stats-bar">
+		<div class="ab-stat">
+			<span class="ab-stat-label"><?php esc_html_e( 'Monthly Spend', 'prautoblogger' ); ?></span>
+			<span class="ab-stat-value">$<?php echo esc_html( number_format( $monthly_spend, 2 ) ); ?> <small>/ $<?php echo esc_html( number_format( $budget, 2 ) ); ?></small></span>
+		</div>
+		<div class="ab-stat">
+			<span class="ab-stat-label"><?php esc_html_e( 'Prompts Table', 'prautoblogger' ); ?></span>
+			<span class="ab-stat-value">
+				<?php if ( PRAutoBlogger_Prompt_Registry::is_available() ) : ?>
+					<span class="pab-badge pab-badge-ok"><?php esc_html_e( 'Available', 'prautoblogger' ); ?></span>
+				<?php else : ?>
+					<span class="pab-badge pab-badge-warn"><?php esc_html_e( 'Unavailable — using defaults', 'prautoblogger' ); ?></span>
+				<?php endif; ?>
+			</span>
+		</div>
+	</div>
+
+	<?php if ( 'saved' === $save_result['status'] ) : ?>
+		<div class="ab-save-notice notice notice-success is-dismissible">
+			<span class="dashicons dashicons-saved"></span> <?php echo esc_html( $save_result['message'] ); ?>
+		</div>
+	<?php elseif ( 'error' === $save_result['status'] ) : ?>
+		<div class="ab-save-notice notice notice-error is-dismissible">
+			<span class="dashicons dashicons-warning"></span> <?php echo esc_html( $save_result['message'] ); ?>
+		</div>
+	<?php endif; ?>
+
+	<?php
+	$niche = (string) get_option( 'prautoblogger_niche_description', '' );
+	$niche_preview = '' !== $niche ? mb_strimwidth( $niche, 0, 80, '…' ) : '';
+	?>
+	<div class="pab-global-context-note">
+		<span class="dashicons dashicons-info-outline"></span>
+		<?php if ( '' !== $niche_preview ) : ?>
+			<?php
+			printf(
+				/* translators: %s = truncated niche description */
+				esc_html__( 'Niche context (used by all stages): "%s"', 'prautoblogger' ),
+				esc_html( $niche_preview )
+			);
+			?>
+		<?php else : ?>
+			<?php esc_html_e( 'Niche description not set — edit in Settings → Content.', 'prautoblogger' ); ?>
+		<?php endif; ?>
+	</div>
+
+	<div class="pab-pipeline-layout">
+
+		<nav class="pab-step-rail" aria-label="<?php esc_attr_e( 'Pipeline steps', 'prautoblogger' ); ?>">
+			<?php foreach ( $steps as $i => $step ) : ?>
+				<?php $is_active = $step['id'] === $active_step['id']; ?>
+				<a href="<?php echo esc_url( add_query_arg( 'step', $step['id'], $base_url ) ); ?>"
+				   class="pab-step-btn <?php echo $is_active ? 'pab-step-btn--active' : ''; ?>"
+				   aria-current="<?php echo $is_active ? 'page' : 'false'; ?>">
+					<span class="pab-step-num"><?php echo esc_html( (string) ( $i + 1 ) ); ?></span>
+					<span class="dashicons <?php echo esc_attr( $step['icon'] ); ?> pab-step-icon"></span>
+					<span class="pab-step-label"><?php echo esc_html( $step['label'] ); ?></span>
+				</a>
+			<?php endforeach; ?>
+		</nav>
+
+		<div class="pab-step-panel">
+
+			<div class="pab-panel-header">
+				<h2><?php echo esc_html( $active_step['label'] ); ?></h2>
+				<?php if ( ! empty( $active_step['description'] ) ) : ?>
+					<p class="pab-panel-desc"><?php echo esc_html( $active_step['description'] ); ?></p>
+				<?php endif; ?>
+			</div>
+
+			<?php if ( ! empty( $step_data['model_option'] ) ) : ?>
+			<div class="pab-section">
+				<h3 class="pab-section-title"><?php esc_html_e( 'Model', 'prautoblogger' ); ?></h3>
+				<form method="post"
+				      action="<?php echo esc_url( add_query_arg( 'step', $active_step['id'], $base_url ) ); ?>"
+				      class="pab-model-form">
+					<?php wp_nonce_field( $nonce_action, $nonce_field ); ?>
+					<input type="hidden" name="pipeline_action" value="save_model" />
+					<input type="hidden" name="model_option" value="<?php echo esc_attr( $step_data['model_option'] ); ?>" />
+					<div class="pab-model-picker-wrap">
+						<?php
+						$renderer = new PRAutoBlogger_Pipeline_Settings_Renderer();
+						$renderer->render_model_picker(
+							$step_data['model_option'],
+							$step_data['model_value'],
+							array( 'capability' => $active_step['capability'] ?? 'text→text' )
+						);
+						?>
+					</div>
+					<p class="pab-field-note">
+						<?php esc_html_e( 'Changing the model here also updates the corresponding field in Settings → AI Models.', 'prautoblogger' ); ?>
+					</p>
+					<button type="submit" class="ab-btn ab-btn-secondary ab-btn-sm">
+						<?php esc_html_e( 'Save Model', 'prautoblogger' ); ?>
+					</button>
+				</form>
+			</div>
+			<?php endif; ?>
+
+			<?php if ( ! empty( $step_data['params'] ) ) : ?>
+			<div class="pab-section">
+				<h3 class="pab-section-title"><?php esc_html_e( 'Parameters', 'prautoblogger' ); ?></h3>
+				<table class="pab-params-table">
+					<?php foreach ( $step_data['params'] as $param_name => $param_value ) : ?>
+					<tr>
+						<th><?php echo esc_html( $param_name ); ?></th>
+						<td><code class="pab-mono"><?php echo is_array( $param_value ) ? esc_html( wp_json_encode( $param_value ) ) : esc_html( (string) $param_value ); ?></code></td>
+					</tr>
+					<?php endforeach; ?>
+				</table>
+				<p class="pab-field-note">
+					<?php esc_html_e( 'Parameters are defined in the prompt registry defaults. Editing params is a Phase 2b feature.', 'prautoblogger' ); ?>
+				</p>
+			</div>
+			<?php endif; ?>
+
+			<?php if ( ! empty( $step_data['system'] ) ) :
+				$panel        = $step_data['system'];
+				$panel_title  = __( 'System Instructions', 'prautoblogger' );
+				$step_id      = $active_step['id'];
+				$is_writer    = ( 'writer' === $step_id );
+				$writing_mode = (string) get_option( 'prautoblogger_writing_pipeline', 'multi_step' );
+				include PRAUTOBLOGGER_PLUGIN_DIR . 'templates/admin/pipeline-settings-prompt-panel.php';
+			endif; ?>
+
+			<?php foreach ( $step_data['agent_panels'] as $key => $panel ) :
+				$panel_title  = sprintf(
+					/* translators: %s = registry key e.g. 'content.draft' */
+					__( 'Prompt: %s', 'prautoblogger' ),
+					$key
+				);
+				$step_id      = $active_step['id'];
+				$is_writer    = ( 'writer' === $step_id );
+				$writing_mode = (string) get_option( 'prautoblogger_writing_pipeline', 'multi_step' );
+				include PRAUTOBLOGGER_PLUGIN_DIR . 'templates/admin/pipeline-settings-prompt-panel.php';
+			endforeach; ?>
+
+		</div>
+	</div>
+</div>

templates/admin/pipeline-settings-prompt-panel.php

@@ -0,0 +1,107 @@
+<?php
+/**
+ * Partial: Pipeline Settings — single prompt editor panel.
+ *
+ * Variables passed by pipeline-settings-page.php:
+ *   array  $panel        — prompt panel data from Renderer::build_prompt_panel_data().
+ *   string $nonce_action — nonce action string.
+ *   string $nonce_field  — nonce field name.
+ *   string $step_id      — active step id (for the form action URL).
+ *   string $base_url     — admin.php?page=prautoblogger-pipeline base URL.
+ *   string $panel_title  — human-readable title for this panel's h3.
+ *   string $writing_mode — (optional) current writing pipeline mode for Writer step.
+ *   bool   $is_writer    — whether this is the Writer step.
+ *
+ * @see templates/admin/pipeline-settings-page.php — Includes this partial.
+ */
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+$key        = $panel['key'];
+$css_key    = str_replace( '.', '-', $key );
+$form_key   = str_replace( '.', '-', $key );
+
+// Writer-step inactive detection.
+$is_inactive = false;
+if ( isset( $is_writer ) && $is_writer ) {
+	$writing_mode     = isset( $writing_mode ) ? $writing_mode : (string) get_option( 'prautoblogger_writing_pipeline', 'multi_step' );
+	$single_pass_keys = array( 'content.single_pass' );
+	$multi_step_keys  = array( 'content.outline', 'content.draft', 'content.polish' );
+	$is_inactive      = ( 'single_pass' === $writing_mode && in_array( $key, $multi_step_keys, true ) )
+	                 || ( 'multi_step' === $writing_mode && in_array( $key, $single_pass_keys, true ) );
+}
+?>
+<div class="pab-section">
+	<h3 class="pab-section-title">
+		<?php echo esc_html( $panel_title ); ?>
+		<span class="pab-version-badge">
+			<?php
+			if ( $panel['active_version'] > 0 ) {
+				printf( esc_html__( 'v%d', 'prautoblogger' ), (int) $panel['active_version'] );
+			} else {
+				esc_html_e( 'default', 'prautoblogger' );
+			}
+			?>
+		</span>
+		<?php if ( $panel['is_default'] ) : ?>
+			<span class="pab-badge pab-badge-ok"><?php esc_html_e( 'Using default', 'prautoblogger' ); ?></span>
+		<?php endif; ?>
+	</h3>
+
+	<?php if ( $panel['version_count'] > 0 ) : ?>
+		<p class="pab-version-meta">
+			<?php
+			printf(
+				/* translators: 1: version count, 2: author, 3: date */
+				esc_html__( '%1$d version(s) stored. Active: by %2$s on %3$s.', 'prautoblogger' ),
+				(int) $panel['version_count'],
+				esc_html( $panel['author'] ),
+				esc_html( $panel['created_at'] )
+			);
+			?>
+		</p>
+	<?php endif; ?>
+
+	<?php if ( $is_inactive ) : ?>
+		<p class="pab-inactive-note">
+			<span class="dashicons dashicons-hidden"></span>
+			<?php
+			printf(
+				/* translators: %s = current writing mode */
+				esc_html__( 'Inactive in current mode (%s). Edit to prepare for mode switch.', 'prautoblogger' ),
+				esc_html( $writing_mode )
+			);
+			?>
+		</p>
+	<?php endif; ?>
+
+	<form method="post"
+	      action="<?php echo esc_url( add_query_arg( 'step', $step_id, $base_url ) ); ?>"
+	      class="pab-prompt-form">
+		<?php wp_nonce_field( $nonce_action, $nonce_field ); ?>
+		<input type="hidden" name="pipeline_action" value="save_prompt" />
+		<input type="hidden" name="prompt_key" value="<?php echo esc_attr( $form_key ); ?>" />
+
+		<textarea name="prompt_body"
+		          id="pab-prompt-<?php echo esc_attr( $css_key ); ?>"
+		          class="pab-prompt-editor"
+		          rows="10"
+		          spellcheck="false"><?php echo esc_textarea( $panel['body'] ); ?></textarea>
+
+		<div class="pab-prompt-actions">
+			<button type="submit" class="ab-btn ab-btn-secondary ab-btn-sm">
+				<?php esc_html_e( 'Save (creates new version)', 'prautoblogger' ); ?>
+			</button>
+			<?php if ( ! $panel['is_default'] ) : ?>
+			<button type="submit"
+			        name="pipeline_action"
+			        value="reset_prompt"
+			        class="ab-btn ab-btn-outline ab-btn-sm pab-btn-reset"
+			        onclick="return confirm('<?php esc_attr_e( 'Reset to factory default? This creates a new version.', 'prautoblogger' ); ?>');">
+				<?php esc_html_e( 'Reset to default', 'prautoblogger' ); ?>
+			</button>
+			<?php endif; ?>
+		</div>
+	</form>
+</div>