chore: bump submodules to Miden v0.15 + align parent docs

[Keinberger]

What & why

Points the two template submodules at their Miden v0.15 commits and aligns the parent-level docs with the v0.15 source-repo renames. The parent repo has no direct Miden SDK dependency — it "gets v15" by moving its gitlink pointers and keeping CLAUDE.md / README.md consistent.

Submodule bumps

Submodule	Old SHA	New SHA (pinned)	Branch	Upstream status
project-template	5270c0a	80394cd	chore/sync-skills-v15	Open PR 0xMiden/project-template#52 — head matches the pin; unmerged (not in project-template main).
frontend-template	8a9fcf0	c5c3ad1	kbg/chore/v15-migration	v0.15 migration landed via merged PR 0xMiden/frontend-template#21 (squash). The pin is a follow-up chore(skills): sync frontend skills to v0.15 commit one commit on top of #21, currently the branch head, not yet in main and with no open PR of its own.

• project-template 80394cd — chore(skills): sync skills to miden v0.15 (2026-07-01)
• frontend-template c5c3ad1 — chore(skills): sync frontend skills to v0.15 from 0xMiden/agent-tools#12 (2026-07-01)

Both pinned commits are unmerged by design — this PR pins the v0.15 template commits intentionally. Note the asymmetry above: project-template's pin is on an open PR (#52), while frontend-template's v0.15 work already merged (#21) and the pin is a small follow-up skills-sync commit that has no open PR of its own. If either branch is force-pushed/rebased or the frontend commit is superseded, re-pin to the new head and re-bump.

Parent-doc alignment

Derived from the actual v0.15 submodule skill diffs. The v0.15 source-guide skills renamed the repositories they map, so the parent docs were updated to match:

• miden-base → protocol (0xMiden/protocol, crate miden-protocol)
• miden-client → rust-sdk (Rust client) for rust-sdk-source-guide; → web-sdk for frontend-source-guide
• compiler, tutorials unchanged

Edits (4 lines, CLAUDE.md ×3 + README.md ×1):

• CLAUDE.md — rust-sdk-source-guide row → protocol, compiler, rust-sdk, tutorials
• CLAUDE.md — frontend-source-guide row → web-sdk
• CLAUDE.md — Factuality rule repo list → protocol, compiler, rust-sdk, web-sdk, tutorials
• README.md — "go deeper" verify-in-source list → protocol, rust-sdk, web-sdk, compiler, tutorials

Everything else was "no change" and verified so:

• No skills renamed / added / removed in either template — all 7 project + 8 frontend skill files were modified in place, so the Skill Sources tables' structure is unchanged.
• agent-tools still has exactly 22 skills (no new "protocol" skill), so the parent's "22 upstream / 9 upstream-only / 13 mirrored" counts are accurate — unchanged.
• The agent-tools contributor skills (rust-client-patterns, idxdb-patterns, wasm-bridge) are not v0.15-migrated and still reference miden-client; the parent descriptions of them are left as miden-client on purpose so they keep matching the real upstream skills.
• The migrated miden-client-cli skill still invokes the CLI as miden client (via midenup) — unchanged.
• No Quick-Reference command form changed (cargo miden build, cargo test -p integration, validate_local, miden-node bundled start, yarn dev, npx vitest --run all still valid).
• No 0.14 version strings existed in parent-level files (and none introduced).

Verification log

• git submodule status → +80394cd project-template, +c5c3ad1 frontend-template (pinned SHAs).
• Both pins re-confirmed to resolve on their submodule remotes (git fetch + git cat-file -t <sha> → commit) and are the current head of their named branch; both are unmerged (not in their submodule main).
• git grep "0\.14" over parent-tracked files (excluding submodules) → 0 matches.
• git grep "miden-base" over parent-tracked files → 0 matches (all migrated to protocol).
• Parent completion hook verify-all.sh:
  • project-template gate (cargo test -p integration --release, cargo-miden 0.9.0): PASS — v0.15 contracts (counter-account, increment-note) compile and the counter_test MockChain integration test passes (test result: ok. 1 passed; 0 failed, exit 0; only a benign wide-arithmetic compiler warning).
  • frontend-template gate: N/A — the v0.15 checkout requires @miden-sdk/* 0.15.3 but the local node_modules is from the prior v0.14 checkout. Making it pass needs a fresh v0.15 yarn install, which is frontend-template setup owned by its own PR/CI and would mutate the submodule working tree (out of scope for a pointer bump). The frontend v0.15 build/test is covered by frontend-template#21's own CI.

Scope

• No SDK code touched in the parent; submodule working trees changed only by the pinned checkout (gitlink pointers only).
• .gitmodules left unchanged (pins are commits, not branches).