Platform detection is implemented twice, and one of the two is dead code

Platform detection is implemented twice. One of the two implementations is unreachable, and the two disagree by construction because nothing keeps them in sync.

## The live implementation

`src/lib/detect-platform/detect-platform.ts` runs four tiers — URL patterns, response headers, source markers, path probes — and returns `{ platform, confidence, signals }`. `captureWebsite` calls it in `src/lib/capture.ts` and routes the result through `findAdapter`.

## The dead implementation

`PlatformAdapter.detect(url): boolean` is declared in `src/types.ts` and implemented by all nine adapters. It has **zero call sites**. The only occurrence of `.detect(` anywhere in `src/` is a comment in `src/adapters/default/index.ts` explaining that nothing calls it:

```
// the pipeline selects adapters by their .detect() method anyway.
```

Adapter selection is by id, in `src/adapters/resolve-adapter.ts`.

Six of the nine implementations already unconditionally `return false`, each with its own comment saying detection really happens in `detect-platform.ts` — `default`, `godaddy-wm`, `hostinger`, and `hubspot` all say so explicitly. The method has been understood as dead for a while; it just was not removed.

The remaining five carry regexes that are literal duplicates of the live `URL_PATTERNS` table:

| Adapter | Regex, duplicated in both `adapters//index.ts` and `detect-platform.ts` |
|---|---|
| wix | `/wixsite\.com\|wix\.com/i` |
| shopify | `/myshopify\.com\|shopify\.com/i` |
| squarespace | `/squarespace\.com/i` |
| webflow | `/webflow\.io\|webflow\.com/i` |
| weebly | `/weebly\.com/i` |

Adding or correcting a platform pattern means editing two files, and editing only one produces no error.

`PlatformAdapter.probe?` is in the same state: declared in `src/types.ts`, zero implementations, zero call sites.

Counting only what is live on `main`, `PlatformAdapter` has seven members, of which two are dead and one (`discover`) is `Promise` — tracked separately in #131.

## Proposed change, in two steps

**Step 1 — `detect`. Done in #135.** Delete it from `PlatformAdapter` and all nine adapters, leaving `detect-platform.ts` as the single source of platform identification, and migrate the URL-pattern coverage onto the live detector.

**Step 2 — `probe`. Sequenced after #119.** The two call sites live in `src/ui/inspect.tsx` and `src/mcp-server/handlers/inspect.ts`, and `inspect` is one of the ten CLI verbs #119 removes. Deleting them now means modify/delete conflicts against a −124k-line PR, to remove code already scheduled for removal. Once #119 lands, `inspect` is gone, both unreachable call sites go with it, and dropping the declaration is a one-line change against zero callers.

## Acceptance

- Exactly one place in the tree knows what a Wix URL looks like. *(step 1)*
- `PlatformAdapter` declares only members with call sites. *(step 2)*
- No behaviour change to detection results — both steps remove surfaces nothing reaches, so detection output must stay identical.

## Follow-up, deliberately not in scope

`tsconfig.json` sets `strict: true` but not `noUnusedLocals` / `noUnusedParameters`, which is the condition that lets dead declarations survive a clean `tsc --noEmit`. Turning both on today reports 51 errors on `main`, the majority in the WordPress-reconstruction tree that #119 deletes. Fixing them now would be work thrown away and merge conflict against a −124k-line open PR, so the flag change should land after #119 and is tracked separately.

---

*AI assistance: researched and written by Claude via Claude Code. The dead-code claims come from reading the tree and grepping for call sites; the 51-error figure is from running `tsc --noEmit --noUnusedLocals --noUnusedParameters` against `main`. Chris Huber orchestrated and reviewed the work and is responsible for what is filed here.*

*Correction: an earlier revision of this issue claimed orphaned imports in `src/types.ts` and `src/adapters/shared.ts`. That is wrong for `main` — those symbols are live there. They are orphaned only on the `refactor/remove-wordpress-reconstruction` branch, where the code they served was deleted and the imports were left behind. That belongs to #119 and has been removed from this issue.*

Start with src/types.ts, src/lib/detect-platform/detect-platform.ts, src/lib/capture.ts, src/adapters/resolve-adapter.ts, and the nine adapter index.ts files; compare the live detector with the adapter declarations and implementations. The probe call sites are src/ui/inspect.tsx and src/mcp-server/handlers/inspect.ts, but this step waits for #119. Done means only live members remain and detection output is unchanged.

Written by the indexing model from the issue text.