Write a poem within precise formal constraints

Write an original poem about Returning to an empty family workshop, creating this emotional movement: Begin with estrangement and end with quiet permission to make something new.
Follow these formal constraints: 12 lines in three four-line stanzas; free verse; no end rhyme required.
Use this image bank: A sawdust-covered window, a chipped blue mug, pencil marks on a doorframe, a new blade still wrapped in paper.

Build the poem around concrete images and a change in perception. Prefer specific nouns and active verbs to abstract statements about emotion. Use the supplied images selectively; do not force every image into the poem. Avoid stock phrases and imitation of a named poet.

Return the poem first, followed by a compact form check listing line count, stanza pattern, rhyme or syllable requirements when requested, and any deliberate exception. If constraints conflict, explain the conflict and offer the closest workable form before writing. Do not claim perfect meter without showing how the requested pattern was checked.