Projects tool: search can return images, write switches split, and project document reads are tracked

What

The Projects tool lets Claude search and write documents in a claude.ai Project. Several parts of it changed:

• project_search results can now include images, as image blocks next to the text. Before, results were text only. Images are removed when a result is stored and put back when the result is remapped (restoreTransientForRemap).
• project_search now takes a number from the switch tengu_pebble_harbor, held between 0 and 4. Before, it took only n. Nothing has been read about this switch.
• tengu_lovely_rain alone now gates writing into the document in view, and tengu_lucky_nebula only gates the variant that writes by file path. Before, writing needed both. tengu_toasty_owl is unchanged. For both tengu_lovely_rain and tengu_lucky_nebula, the flag server returned off for this site's account and for the anonymous baseline, and no reading has been taken under this release.
• Writes and deletes go through a new approval check.
• Stream events gain an internal optional owed_rows field. It lists the IDs of project_doc_reads rows, which record Claude Code reading a claude.ai Project's documents.
• After a turn whose attachments include project_doc_reads, Claude Code starts a lookup of hashes (fingerprints) of those documents. The environment variable CLAUDE_CODE_PROJECT_DOC_LOOK_TIMEOUT_MS sets how long the lookup may take, and on a timeout it gives up for the rest of the session. In headless mode (running without the interactive screen) the ID of the project_doc_reads attachment is also collected into a list.

Why

Claude can now get pictures, not just text, back from a project search. Whether each kind of write is available depends on a different server switch than before. If the document lookup slows you down, CLAUDE_CODE_PROJECT_DOC_LOOK_TIMEOUT_MS bounds it.