[zxch3n]

Long strings inserted through loro_delta::text_delta::TextDelta silently lost their final chunk: 129, 256, and 257 ASCII bytes became 128, 128, and 256 bytes. Middle insertion could also panic when a UTF-8 character crossed chunk capacity. These chunking defects have existed since DeltaRope was introduced in #327.

Share byte-capacity, UTF-8-aware chunking between long appends and middle insertion, including the final slice. Preserve the short-string fast path and attributes on every chunk.

Partial UTF-8 chunks expose a B-tree batch ordering defect: inserting 127 x characters plus é between the b and c in ordinary a followed by bold bc can move the x characters before b. Fix DeltaRope::insert_values in the published crate itself: buffer multiple items and insert back to front using the returned start cursor from single-item insertion. Empty and single-item inputs avoid batch allocation. This works with registry generic-btree 0.10.7, without requiring the workspace patch or a new B-tree release.

Also fix the in-tree B-tree's adjacent-left-leaf selection and end cursor after merging a batch prefix. The vendored fork is excluded from publishing, so these changes are tested separately and are not the basis for downstream correctness.

Add scripts/test-delta-published-deps.sh to CI. It creates the actual .crate archive, extracts it outside the workspace, pins registry generic-btree to the minimum supported 0.10.7, and runs all packaged tests independently of [patch.crates-io].

Regression coverage includes length boundaries; 2/3/4-byte UTF-8 characters; append and middle insertion; preservation of surrounding attributes; 1,000 sequential UTF-8 edits compared against String; B-tree leaf/parent boundaries, caches, and subsequent insertion. Include a Rust-only changeset and document the insertion and publishing invariants in context/text-delta-chunking.md.

Validation:

• Confirmed the attributed middle-insertion regression fails before the fix.
• Confirmed the B-tree leaf-end regression detects a stale cursor if only the adjacent-leaf fix is applied.
• bash scripts/test-delta-published-deps.sh --offline: all 44 packaged tests passed with registry generic-btree 0.10.7, including all 22 text integration tests.
• cargo test --offline -p generic-btree -p loro-delta: 70 passed, 3 existing ignored tests; doctests passed.
• cargo clippy --offline -p generic-btree -p loro-delta --all-targets -- -D warnings: passed.
• Rustfmt, Bash syntax, and git diff --check: passed.

[github-actions]

WASM Size Report

• Original size: 3502.46 KB
• Gzipped size: 1168.69 KB
• Brotli size: 819.70 KB