feat(tokens): add HTLC lock, claim, and reclaim service layer

[atharrva01]

Summary

Week 3 of issue #66's deliverable 3 (HTLC locks). Adds the FSC view layer driving Panurus's existing HTLC protocol (token/services/interop/htlc): Lock (+ the recipient-side LockAccept responder), Claim, and Reclaim, mirroring owner/service/fsc.go's existing TransferView/RedeemView shape. No REST surface yet — that's next (week 4), once this is proven.

Ported from the pre-rename fabric-token-sdk integration/ package's own reference views (removed from the published module at v0.13.0; per mentor guidance, that module is for Panurus's own internal parts and isn't meant to be imported, so the logic is carried locally instead), adjusted for v0.18.0's current API:

• Claim, Reclaim, and Outputs all gained a leading ctx.Context param since the reference was written.
• Dropped ttx.WithAuditor — no auditor identity exists anywhere in this app's config, and the live Transfer/Redeem views already pass zero TxOptions; HTLC follows the same pattern.
• Uses htlc.NewTransaction (named signer) instead of the reference's NewAnonymousTransaction: the latter needs an "idemix" FSC-native identity this app's fabric3 config has never set up (nothing else here uses an anonymous transaction), so it fails "identity [idemix] not found" instead of a real bug. Named signing avoids that entirely and matches every other flow in this app.
• Recipient-identity exchange uses htlc's own ExchangeRecipientIdentities/RespondExchangeRecipientIdentities rather than fsc.go's getRemoteIdentity/RequestRecipientIdentity: the lock script asserts a specific (sender, recipient) identity pair on both sides, and only the htlc-native exchange guarantees both parties agree on the same pair. The Bind step from getRemoteIdentity is still needed first.
• Every new Options struct carries a TMSID selector (via the existing common/views.ServiceOpts/TxOpts helpers), so a second TMS is additive rather than a breaking change.

Test plan

• go build/go vet clean on both the default and fabricx build tags
• Verified against a live fabric3 network via a temporary debug HTTP handler (removed before this commit): lock→claim moved 10 TOK from alice to dan correctly; a second lock with a 10s deadline, reclaimed after expiry, returned the tokens to alice and left the original pre-image unclaimable