chore(morph): reinforce morph mechanism

[yzuyr]

Summary by CodeRabbit

• Bug Fixes
  • Preserved focus, cursor/selection, and layout/input subtrees during in-place updates and navigation.
  • Improved keyed slot reconciliation (including shrink/leave transitions) to avoid unintended removals.
  • Synced <select> live selection without clobbering user choice, including keyed option reorders.
  • Preserved controller-owned attributes via data-morph-preserve and added dev warnings for updates that may replace stateful elements (iframe/video/audio/canvas).
  • Avoided unnecessary DOM changes when output is unchanged.
• Documentation
  • Expanded the guide with identity-sensitive keying guidance and data-morph-preserve examples.
• Chores
  • Bumped package versions across the ecosystem and templates.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Reviewing files that changed from the base of the PR and between fa576f2 and 7e1018b.

📒 Files selected for processing (2)

• packages/ilha/src/index.test.ts
• packages/ilha/src/index.ts

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📝 Walkthrough

Walkthrough

The island runtime hardens DOM morphing with keyed slot reconciliation, focus and form-state preservation, transition guards, and identical-output fast paths. Regression tests, render documentation, and package version requirements are updated accordingly.

Changes

Morph engine hardening

Layer / File(s)	Summary
Morph reconciliation contracts packages/ilha/src/index.ts	Adds preserved-attribute handling, data-key and slot-based identity matching, destructive replacement warnings, and leaving-slot safeguards.
Focus and form synchronization packages/ilha/src/index.ts	Synchronizes template-driven <select> state and restores input, selection, and contenteditable state after morphing.
Render fast path and slot rehoming packages/ilha/src/index.ts	Tracks rendered output, skips identical markup morphs while updating slot props, and adjusts slot teardown and rehoming during list changes.
Regression coverage and release alignment packages/ilha/src/index.test.ts, packages/router/src/inplace-update.test.ts, apps/website/src/pages/(content)/guide/island/render.mdx, packages/*/package.json, apps/website/package.json, templates/*/package.json	Adds regression coverage for slot stability, forms, preserved attributes, transitions, identical output, and warnings; documents the new morph contracts and updates package versions and requirements.

Estimated code review effort: 4 (Complex) | ~60 minutes

Sequence Diagram(s)

sequenceDiagram
  participant IslandRenderEffect
  participant applyMorph
  participant morphChildren
  participant DOM
  participant MountedSlot
  IslandRenderEffect->>IslandRenderEffect: compare output with lastRendered
  IslandRenderEffect->>MountedSlot: update props when output is identical
  IslandRenderEffect->>applyMorph: reconcile changed output
  applyMorph->>morphChildren: morph the wrapped host
  morphChildren->>DOM: preserve focus, form state, and keyed nodes
  morphChildren->>MountedSlot: retain, rehome, or replace slot hosts

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Possibly related PRs

• ilhajs/ilha#23: Related keyed slot marker and slot-id reconciliation changes.
• ilhajs/ilha#61: Related handling of reused slot ids and island remounting.
• ilhajs/ilha#68: Related keyed morph reconciliation and live form-state synchronization.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title matches the PR’s main focus on strengthening the morph engine and reconciliation behavior.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch chore/ilha-reinforce-morph

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[coderabbitai]

Actionable comments posted: 3

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/ilha/src/index.ts`:
- Around line 3562-3573: The list reconciliation logic around listShrunk and
teardownMountedSlot currently remounts every surviving positional slot whenever
the total slot count decreases. Track the actual positional divergence caused by
the removed slot(s), and tear down only p: slots at or after that affected
position; preserve earlier positional slots and their state, effects, DOM, and
focus.
- Around line 600-619: Update restoreFocusAfterMorph so document.activeElement
=== active does not return before restoring selection or contenteditable ranges.
Only skip the focus() call when the element is already active, while continuing
to apply the selection and range restoration logic for connected elements.
- Around line 525-533: Update the select-option state tracking around
syncAttributes and morphChildren to preserve each option’s pre-morph selected
state by option identity rather than array index. Compare each resulting option
against its corresponding original option identity, and only run the o.selected
reset loop when an option’s selected attribute state actually changed; keyed
reorders without attribute changes must preserve the user’s live selection.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 6c892942-86d5-4678-a938-3d75fc49a567

📥 Commits

Reviewing files that changed from the base of the PR and between 2073a67 and fa576f2.

⛔ Files ignored due to path filters (1)

• bun.lock is excluded by !**/*.lock

📒 Files selected for processing (12)

• apps/website/package.json
• apps/website/src/pages/(content)/guide/island/render.mdx
• packages/ilha/package.json
• packages/ilha/src/index.test.ts
• packages/ilha/src/index.ts
• packages/router/package.json
• packages/router/src/inplace-update.test.ts
• packages/store/package.json
• templates/elysia/package.json
• templates/hono/package.json
• templates/nitro/package.json
• templates/vite/package.json