Graph: make index exhaustion atomic

[fubhy]

Summary

• Allow Number.MAX_SAFE_INTEGER as the final node or edge index and represent the following allocator state internally as exhausted.
• Reject later allocations with stable GraphErrors before cache, map, adjacency, or cycle-state mutation, while preserving endpoint-validation precedence for exhausted edge allocators.
• Derive exhausted allocator state from Graph snapshots and Schema.Graph decoding that end at the maximum safe index.

Plan

• PR ID: S03
• Depends on: Graph: ignore allocator history in equality #7274 (graph-s02-equality-allocators)
• Deferred: benchmark/runtimeperf validation is intentionally out of scope for this cycle.
• Retarget: after Graph: ignore allocator history in equality #7274 merges, retarget this PR to main.

Validation

• pnpm lint-fix
• pnpm test --run packages/effect/test/Graph.test.ts packages/effect/test/schema/Graph.test.ts
• pnpm check
• git diff --check

Changeset

• .changeset/tidy-graphs-stop.md (effect, patch)

[changeset-bot]

🦋 Changeset detected

Latest commit: d77445f

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 30 packages

Name	Type
effect	Patch
@effect/ai-anthropic	Patch
@effect/ai-openai	Patch
@effect/ai-openai-compat	Patch
@effect/ai-openrouter	Patch
@effect/atom-react	Patch
@effect/atom-solid	Patch
@effect/atom-vue	Patch
@effect/docgen	Patch
@effect/doctest	Patch
@effect/openapi-generator	Patch
@effect/opentelemetry	Patch
@effect/platform-browser	Patch
@effect/platform-bun	Patch
@effect/platform-deno	Patch
@effect/platform-node	Patch
@effect/platform-node-shared	Patch
@effect/sql-clickhouse	Patch
@effect/sql-d1	Patch
@effect/sql-libsql	Patch
@effect/sql-mssql	Patch
@effect/sql-mysql2	Patch
@effect/sql-pg	Patch
@effect/sql-pglite	Patch
@effect/sql-sqlite-bun	Patch
@effect/sql-sqlite-do	Patch
@effect/sql-sqlite-node	Patch
@effect/sql-sqlite-react-native	Patch
@effect/sql-sqlite-wasm	Patch
@effect/vitest	Patch

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