fix(storage): allow digits in SQL table names and return errors instead of panicking

[AkramBitar]

Fixes #2034

escapeForTableName omitted digits from its character allow-list and panicked on anything outside it, while buildTableNames formatted through MustFormat — so a channel name like channel1 crashed the node at store-construction time, with no recover() anywhere in the chain.

• digits are now accepted, validated against the identifier actually emitted (prefix included);
• unsupported characters return a configuration error instead of panicking.

Regression tests cover the real driver-construction and NewStoreServiceManager paths, not just the escaping helper, plus a FuzzGetTableNamesNoPanic target wired into the nightly fuzz matrix.

[github-actions]

📊 Token Validation Benchmark

Comparison of this PR against the base branch. 🟢 improvement · 🔴 regression · ➖ within ±1.0% noise.

Variant	Benchmark	Params	Workers	TPS (base → PR)	Δ TPS
csp	BenchmarkAPIGRPC	f=1, nc=4, w=token-validation-service	4	118 → 117	➖ -0.3%
csp	BenchmarkLocalTokenValidation	out-tokens=2in-tokens=2	4	104 → 104	➖ +0.1%
ipa	BenchmarkAPIGRPC	f=1, nc=4, w=token-validation-service	4	70 → 70	➖ -0.1%
ipa	BenchmarkLocalTokenValidation	out-tokens=2in-tokens=2	4	76 → 76	➖ -0.0%

[github-actions]

📊 Token Validation Benchmark

Comparison of this PR against the base branch. 🟢 improvement · 🔴 regression · ➖ within ±1.0% noise.

Variant	Benchmark	Params	Workers	TPS (base → PR)	Δ TPS
csp	BenchmarkAPIGRPC	f=1, nc=4, w=token-validation-service	4	117 → 118	➖ +0.3%
csp	BenchmarkLocalTokenValidation	out-tokens=2in-tokens=2	4	104 → 104	➖ +0.2%
ipa	BenchmarkAPIGRPC	f=1, nc=4, w=token-validation-service	4	78 → 78	➖ +0.2%
ipa	BenchmarkLocalTokenValidation	out-tokens=2in-tokens=2	4	79 → 79	➖ -0.4%