PR Vision v0.3.0: per-call cost accountability + LLM call audit trail

P0 security:
- PRV_Gateway_Client: remove response body from RuntimeException (HTTP status only)
- PRV_Capture_Writer: allowlist-only write (prompt/response text, never headers/auth)
- Mandatory capture order: can_afford → probe → persist_result → update_row_cost → write_meta → capture_io
- capture_io last and wrapped in swallowing try/catch

New tables (SCHEMA_VERSION 3):
- prv_call_meta: cost/metadata per call, kept indefinitely
- prv_call_io: rendered prompt + raw response, pruned on retention window (default 90d)

New classes:
- PRV_Call_Meta_Table, PRV_Call_Io_Table: table schema + dbDelta
- PRV_Capture_Writer: metadata + I/O write; security allowlist enforced
- PRV_Prune_Cron: daily prv_daily_prune cron deletes aged prv_call_io rows only
- PRV_Cost_Rollup_Query: MTD summary, model breakdown, drill-down, projection
- PRV_Call_Log_Query: paginated + filtered call-log query + per-call I/O fetch
- PRV_Costs_Page + PRV_Costs_Renderer: Costs admin sub-page (cap progress, bento, model table, drill-down)
- PRV_Call_Log_Page + PRV_Call_Log_Table_Renderer: Call Log admin sub-page (filter bar, paginated table, WCAG AA pagination)
- PRV_Call_Drawer_Renderer: non-modal complementary drawer (5 states: Normal/Pruned/Legacy/Failed/Loading)
- PRV_Call_Drawer_Script: inline JS for drawer (300-line split from renderer)
- PRV_Call_Detail_Ajax: wp_ajax_prv_call_detail AJAX handler
- PRV_Admin_Page_Css: CSS provider (300-line split from PRV_Admin_Page)
- PRV_Probe_Run_Executor: inner probe loop (300-line split from PRV_Probe_Runner)

Updated:
- PRV_Probe_Result: tokens_in/tokens_out params + getters
- Both providers: report tokens_in/tokens_out from usage.prompt_tokens/completion_tokens
- PRV_Probe_Runner: slimmed to lock+UUID+delegation; injects PRV_Capture_Writer
- PRV_Config: get_io_retention_days(); PRV_IO_RETENTION_DEFAULT_DAYS constant
- PRV_Upgrader/Activator/Deactivator/Plugin: register new tables, cron, pages, AJAX
- Settings: retention days field + save in controller
- uninstall.php: DROP both new tables, clear prv_daily_prune cron
- Subnav 4-tab strip (Dashboard | Costs | Call Log | Settings) on all pages
- ARCHITECTURE.md, CHANGELOG.md, CONTEXT.md, CONVENTIONS.md updated

Tests:
- test-capture-writer.php: write_meta, write_io, P0 security (401 record has no key/Bearer/sk-or-)
- test-cost-audit.php: MTD reconciliation, projection, prune, forced capture_io exception, table drops

Agent-Session: peptiderepo-geomonitor-v0.3.0-cost-audit

uninstall.php

@@ -12,6 +12,10 @@
  * prv_last_run_truncated_at -- all purged by the prv_ wildcard DELETE below.
  *
  * v0.2.3 addition: prv_provider_key_enc (encrypted API key) -- also purged
+ *
+ * v0.3.0 additions: prv_call_meta + prv_call_io tables (both DROPped);
+ *   prv_io_retention_days option (purged by wildcard DELETE);
+ *   prv_daily_prune cron hook (cleared in step 4).
  * by the prv_ wildcard DELETE below. No plaintext is stored.
  *
  * @see ARCHITECTURE.md          -- Section Uninstall specification.
@@ -26,12 +30,26 @@ if ( ! defined( 'WP_UNINSTALL_PLUGIN' ) ) {
 
 global $wpdb;
 
-/* ── 1. Drop the custom table ─────────────────────────────────────── */
+/* ── 0. Bootstrap minimum classes for DROP calls ─────────────────── */
+
+require_once plugin_dir_path( __FILE__ ) . 'includes/core/class-prv-autoloader.php';
+PRV_Autoloader::register();
+
+/* ── 1. Drop the custom tables (including v0.3.0 audit tables) ────── */
 
 $table = $wpdb->prefix . 'prv_ai_visibility';
 // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.SchemaChange, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.DirectDatabaseQuery.NoCaching
 $wpdb->query( "DROP TABLE IF EXISTS {$table}" );
 
+// v0.3.0: per-call audit tables (drop io before meta to respect FK intent).
+$io_table = $wpdb->prefix . 'prv_call_io';
+// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.SchemaChange, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.DirectDatabaseQuery.NoCaching
+$wpdb->query( "DROP TABLE IF EXISTS {$io_table}" );
+
+$meta_table = $wpdb->prefix . 'prv_call_meta';
+// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.SchemaChange, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.DirectDatabaseQuery.NoCaching
+$wpdb->query( "DROP TABLE IF EXISTS {$meta_table}" );
+
 /* ── 2. Delete all prv_ prefixed options (v0.1, v0.2, v0.2.3) ───── */
 
 // Covers prv_provider_key_enc (v0.2.3) along with all prior option keys.
@@ -50,3 +68,5 @@ $wpdb->query(
 /* ── 4. Clear any remaining scheduled cron events ─────────────────── */
 
 wp_clear_scheduled_hook( 'prv_weekly_probe' );
+// v0.3.0: daily prune cron.
+wp_clear_scheduled_hook( 'prv_daily_prune' );