paperclip: add sharedBankName config for cross-agent memory sharing

[SeBru1]

Summary

Adds an optional sharedBankName string to the hindsight-integrations/paperclip plugin's instance config. When set, every agent in the company reads/writes the same Hindsight bank — overriding bankGranularity and the default paperclip::{companyId}::{agentId} derivation.

This is a small, additive, backwards-compatible change. No behavior changes for any existing install that doesn't set the new field.

Motivation

The current bankGranularity: [\"company\", \"agent\"] default isolates each agent's memory. That's the right default — memory shouldn't leak across unrelated agents.

But for multi-agent cohorts that need to collaborate on a shared pool of project context (e.g. a CEO/CTO/Staff/QA/Researcher team working a single backlog), there's no first-class way to point them at one bank.

Concrete use case: I run a 5-agent Paperclip company where each agent must see decisions, lessons, and project state created by the others. With current granularity, each agent talks to its own bank — hindsight_recall returns nothing the agent didn't write itself, and cross-agent compound knowledge never accrues.

Workarounds I considered:

• bankGranularity: [\"company\"] collapses to a per-company bank — but the bank ID is still paperclip::{companyId}, which is fine for a single deployment but not when you want a human-readable bank name shared across companies or instances.
• A wrapper plugin re-implementing the same logic against a fixed bank — significant maintenance cost for what's essentially a one-line override.

The cleanest fix is a tiny optional config override. That's this PR.

What changed

• src/bank.ts: extend BankConfig with optional sharedBankName; deriveBankId returns the trimmed value verbatim when set, otherwise falls through to the existing granularity logic unchanged.
• src/manifest.ts: add sharedBankName to instanceConfigSchema so it's configurable from Settings → Plugins → Hindsight Memory.
• src/worker.ts: add the field to the internal PluginConfig type.
• tests/plugin.spec.ts: 4 new tests — 3 unit tests for the override semantics (trimming, empty/whitespace fallthrough, normal override) + 1 integration test that verifies recall routes to the shared bank URL.
• README.md: document the field and add a Shared bank for cross-agent collaboration section.

Backwards compatibility

The field is optional. Existing installs without sharedBankName keep the existing paperclip::{companyId}::{agentId} derivation untouched.

Test plan

• npm run typecheck — clean
• npm test — 19/19 tests pass (15 existing + 4 new)
• npm run build — clean esbuild output
• Verified locally against a 5-agent company: with sharedBankName: \"spool-farm\", recall/retain from all 5 agents now route to the single spool-farm bank.

Notes for review

Happy to adjust naming (sharedBankName vs bankName vs bankOverride), schema placement, or split into smaller commits if preferred. The full change is +89/-8 across 5 files.

[benfrank241]

@SeBru1 thanks! Clean PR and the cross-agent collaboration case is legit. LGTM

[benfrank241]

@SeBru1 — could you rename sharedBankName → bankId and add a dynamicBankId: boolean to match the pattern the other plugins use? same behavior, but a user moving between paperclip/ claude-code / openclaw would see the same field names mean the same thing. otherwise the implementation looks clean.