refactor(dashboard): inline AvatarInitial derivation

[LudoLoops]

Summary

Part of #594. Inline the one-use derived initial in Dashboard AvatarInitial.svelte so the markup reads the current name directly. This preserves reactive updates, uppercase behavior, the empty-name fallback, sizing, and consumer classes. Adds render/rerender coverage and a svforge patch changeset.

Validation

• Targeted AvatarInitial, Dashboard composition, Skeleton-native, and Skeleton-markup tests: 49 passed.
• bun run lint, bun run typecheck, and bun run build:all: passed.
• bash scripts/test-scaffold.sh base: passed.
• Dashboard scaffold build/check passed; its Vitest run had 2 failures because the configured database already contains 13 foreign rows (40 passed, 3 skipped).
• Full bun run test: 1,192 passed; 3 timed out (canary-snapshots, packed user journey, and a real scaffold test under the local run).

This is one small Dashboard derivation tranche; the broader #594 audit remains open.

[LudoLoops]

Review completed — no merge blockers (head 77c4acfaf4bba2bd44dd6c9c2f8cf49e24d778f6).

This focused #594 tranche removes the single-use $derived(initial) from Dashboard AvatarInitial.svelte and directly renders name[0]?.toUpperCase() ?? '?'. The Svelte 5 property expression remains reactive; the name prop contract, sizes, cn() consumer class override, fallback for empty names, and markup are unchanged.

• New component-level render/rerender tests verify name updates, dynamic sizing, consumer classes, and empty-name fallback. Non-blocking test improvement: explicitly rerender or render a lowercase starting letter to assert toUpperCase() (the current test names, Ada and Grace, already start uppercase).
• Verified the generated packages/svforge/src/templates.ts Dashboard entry is identical to the component source. Changeset and Graphify updates are present; no custom CSS or extra abstraction.
• GitHub Actions CI refactor(ui): audit all scaffolded components for a minimal Skeleton v5-first baseline #594 passed on this exact head: required quality job succeeded, including lint, typecheck, dependency audits, manifest freshness, build-all, and the full test suite; main-smoke is expected to skip on PRs. Reported local timeouts and pre-populated Dashboard test-database failures did not recur in the required root CI and do not establish a regression in this display-only refactor.
• No unresolved review discussions; GitHub reports the PR mergeable. The broader audit issue refactor(ui): audit all scaffolded components for a minimal Skeleton v5-first baseline #594 should remain open.

MERGE DECISION: READY TO MERGE.