The modernized Execute Tests screen (gui/templates/execute/execTest.html + api/execute/index.php) rendered the execution form (status buttons, notes, steps, save) but had no attachment functionality: you could not attach a file to a new execution, could not see the attachments of the latest execution on a context, and there was no "Copy attachments from latest execution" checkbox. The legacy screen (inc_exec_img_controls.tpl, inc_exec_show_tc_exec.tpl) provides all three. This was a regression vs. 1.9.20.

1. Frontend had no attachment UI. renderForm() in execTest.html stopped at notes/steps/save — the legacy upload control (attachments.inc.tpl at inc_exec_img_controls.tpl:132), the per-exec attachment list, and the copy checkbox (inc_exec_img_controls.tpl:68-73) were never ported.
2. The BFF save dropped any uploaded file. api/execute/index.php ?action=save read only an application/json body (json_decode(file_get_contents('php://input'))), so a multipart file upload was never inspected. There was no execution-level insertAttachment(..., DB_TABLE_PREFIX.'executions', ...) call and no copy-from-latest logic.
3. The copy-from-latest behavior did not exist in the BFF at all. Legacy execSetResults.php:168-205 copies the latest execution's attachments (execution level + per-step, keyed by step_number) onto the new run before/at save; the modernized screen had no equivalent.

Backend — api/execute/index.php:

• New execTestPayload() helper reads the request body supporting both application/json and multipart/form-data; in multipart mode it decodes the JSON-encoded steps_json field back into steps.
• ?action=save:
  • parses copy_att_from_lexec (accepts 1/true/on/yes);
  • captures testcase::getLatestExecIDInContext($tcversionId, $ctx) with ctx = {testplan_id, platform_id (0 when plan has none), build_id} BEFORE write_execution() (after writing, the new run becomes the latest, so the source must be captured first);
  • after the write, when copy was requested, copies execution-level attachments via tlAttachmentRepository::copyAttachments(..., 'executions') and per-step attachments matched by step_number (identical SQL to the legacy loop);
  • uploads execution-level attachments from the dedicated $_FILES['exec_attachments'] field to insertAttachment(..., DB_TABLE_PREFIX.'executions', ...); the response now carries attachments_uploaded.
• ?action=init exposes new_exec_latest (from $tlCfg->exec_cfg->exec_mode->new_exec == 'latest') so the frontend can gate the copy checkbox exactly like legacy.
• ?action=tcDetails prior-execution object now includes an attachments[] list ({id,title,file_name,file_size,download_url}) so the form can show what a copy would bring over, with a root-absolute /lib/attachments/attachmentdownload.php?id=N download link.

Frontend — gui/templates/execute/execTest.html:

• New renderAttachmentsBlock() below the notes field: prior-execution attachment list (name + size + download link), the "Copy attachments from latest execution" checkbox (only when new_exec_latest AND a prior execution exists AND not read-only), and a multiple file-upload input. No UI change when the panel is in read-only mode (upload hidden).
• saveExecution() switched from a JSON body to FormData (processData:false, contentType:false), appending steps_json, copy_att_from_lexec (only when checked) and each selected file as exec_attachments[].
• New i18n keys (exe.attachments, exe.attachmentsUpload, exe.attachmentsTitle, exe.copyAttFromLatest, exe.noAttachments, exe.priorExecution, exe.download) added to all 10 locale bundles.

• Dedicated exec_attachments[] field, NOT uploadedFile. write_execution() (exec.inc.php:206-216) treats uploadedFile as its own nested per-execution upload and addAttachmentsToExec() contains a var_dump($_FILES['uploadedFile']['name'][0]) (exec.inc.php:1041-1043) that would leak <pre>string(1) "t"</pre> into the JSON save response (observed). The BFF owns the upload via the dedicated field, keeping the response clean and the sink identical to legacy.
• [] suffix is required. PHP builds $_FILES['exec_attachments']['name'] as an array only when the multipart field is named exec_attachments[]; a flat field yields a string, so is_array() was false (first two attempts inserted nothing). The frontend therefore appends exec_attachments[].
• Capture latest-exec before writing. Matches the legacy ordering (execSetResults.php:1733 captures $eid before the copy at 168-205); the latest_exec_by_context view groups by (tcversion_id, testplan_id, build_id, platform_id) — all four supplied.
• Copy checkbox gated on new_exec=='latest' mirrors inc_exec_img_controls.tpl:68-73; under the default 'clean' mode the checkbox is hidden but the direct upload and the prior-execution list still work.
• Alternatives rejected: reusing name="uploadedFile" (would hit the legacy var_dump / nested-array mismatch); naming the field exec_attachments without [] (breaks multi-file array).

• api/execute/index.php — execTestPayload(), save (copy-from-latest + exec-level upload + attachments_uploaded), init (new_exec_latest), tcDetails (prior_execution.attachments[]).
• gui/templates/execute/execTest.html — renderAttachmentsBlock(), FormData saveExecution(), newExecLatestFlag(), fmtBytes().
• gui/templates/i18n/{de,en,es,fr,it,ja,pt,ro,ru,zh}.json — 7 new exe.* keys per bundle.

• 621fb9d91 — fix(execute): attachment upload/list + copy-from-latest on Execute Tests (Refs #792)

#	Case	Result
1	Direct upload on save creates an execution-level attachments row (fk_table=executions) and returns attachments_uploaded:1	PASS
2	Download link /lib/attachments/attachmentdownload.php?id=N returns HTTP 200	PASS
3	With new_exec='latest', copy checkbox visible; checking + save copies the latest execution's attachments (execution + step) onto the new run (copy_att_from_lexec=1)	PASS
4	Copy checkbox hidden under default new_exec='clean' (matches legacy)	PASS
5	Prior-execution attachment list renders (name + size + working download link)	PASS
6	No var_dump pollution in the save JSON response	PASS
7	Read-only mode hides upload + copy checkbox	PASS (code review guard)
8	All 10 i18n bundles valid JSON	PASS
9	Event Viewer events log_level 3/4 → 0 new rows	PASS

Verified 2026-08-31, headless Chrome http://localhost:8082, admin/admin, plan QA Test Plan (id 2) / project QA Project (id 1) / test case QA-1 Login Test (tcversion 4) / build Build 1 (id 1); attachment fixture /tmp/opencode/test_attach.csv (24 B, .csv allowed extension).