Add CCN API reference documentation

[claudioALEPH]

Summary

• Added comprehensive CCN API reference at docs/devhub/api/ccn.md, sourced from the OpenAPI spec (v0.9.3) at http://46.255.204.204:4024/api/docs/
• Covers all 41 endpoints across 12 sections: Messages, Aggregates, Posts, Storage, Accounts, Prices, Programs, Channels, P2P, IPFS, Metrics, and Info
• Replaced the broken REST API sidebar link (/devhub/api-reference/rest — 404) with the new CCN API entry

Content source

All endpoint paths, parameters, types, defaults, and descriptions come directly from the CCN's swagger.json OpenAPI spec. No fabricated examples — response formats reference schema names from the spec.

Test plan

• VitePress build succeeds
• Verify sidebar link navigates correctly
• Spot-check endpoints against the live Swagger UI

[aliel]

change it to https://api3.aleph.im instead of api1
-https://api2.aleph.cloud
+https://api2.aleph.im

[foxpatch-aleph]

Good addition that fills a real gap (replacing a broken 404 link with actual content). The documentation is well-structured and consistently formatted. A few accuracy issues worth addressing: a contradictory min_balance constraint, a misplaced endpoint, inconsistent array parameter notation, and a POST endpoint with no documented request body.

docs/devhub/api/ccn.md (line 519): min_balance lists min: 1 but a default of 0. A minimum of 1 means the default of 0 is not a valid value — these are contradictory. If the API truly enforces min: 1, the default should be omitted or set to 1. Same issue appears in the GET /api/v0/credit_balances table (~line 543). Please verify against the OpenAPI spec.

docs/devhub/api/ccn.md (line 672): "Get Resource Consumed Credits" (GET /api/v0/messages/{item_hash}/consumed_credits) is placed under the Accounts section, but its URL path is under /messages/. This will confuse users looking for it under Messages. Consider moving it to the Messages section, or at minimum adding a cross-reference there.

docs/devhub/api/ccn.md (line 443): The Address Stats (v0) endpoint documents its parameter as addresses[] (PHP/HTML array notation), while every other multi-value parameter in this file uses comma-separated strings (e.g., addresses in List Messages). If v0 genuinely expects repeated query params (?addresses[]=0x1&addresses[]=0x2) rather than a comma-separated string, this difference deserves a note — it's a real usability gotcha.

docs/devhub/api/ccn.md (line 237): The sortBy field for GET /api/v0/aggregates shows the default (last_modified) but unlike other endpoints (e.g., List Messages lists time, tx-time) does not enumerate the allowed values. Worth adding the full set of valid options.

docs/devhub/api/ccn.md (line 696): POST /api/v0/price/recalculate has no documented request body. This is unusual for a POST endpoint — does it accept filters (e.g., address, date range, message type) or is it an admin-only no-body operation? If it requires authorization or has optional parameters, those should be documented here.

docs/devhub/api/ccn.md (line 761): Minor organizational note: the P2P section contains a single endpoint whose path is POST /api/v0/ipfs/pubsub/pub — an IPFS-namespaced path. Consider either merging it into the IPFS section or adding a brief note explaining why a P2P pubsub operation lives under /ipfs/ (historical naming, shared transport, etc.).