Correct TGP documentation and remove legal framing

[magiccodingman]

What changed

This PR corrects the TGP documentation after separating what IPNS and Kubo already provide from what TGP uniquely adds.

Removes legal positioning

• removes docs/tgp/legal-considerations.md
• removes docs/tgp/legal-notice-template.md
• removes legal/compliance language from the README and TGP index
• removes the legal field and legal.md file from the normative v1 documentation examples
• avoids presenting TGP as a compliance, takedown, deletion, or liability mechanism

The remaining limitation language is purely technical: changing a pointer does not remove older CIDs, local removal requires handling every retaining pin/reference and Kubo garbage collection, and third parties may retain copies independently.

Corrects the relationship with IPNS

The documentation now says explicitly that:

• IPNS can already move the same signed identity to a new CID
• IPNS does not inherently publish a browsable history or require all previous targets to remain pinned
• Kubo already provides pin removal and repository garbage collection
• TGP does not invent deletion, unpinning, or retention control

Strengthens TGP's actual rationale

The primary model is now described as a deliberate trade:

Direct IPNS:
IPNS → application CID

TGP:
IPNS → small control bundle → application CID

The additional hop provides:

• a lightweight machine-readable current pointer
• inexpensive freshness checks
• normal immutable caching after resolution
• a stable browser landing point
• an optional index.html resolver/fallback for ordinary and IPFS-aware browsers
• an application-independent seam for routing and fallback behavior
• a consistent boundary for current-only, bounded-history, selected-release, or archival retention policies
• room for future routing metadata without changing every application DAG

Clarifies retention policy

TGP's retention benefit is now framed as organizational and operational, not a new IPFS capability.

TGP supplies a stable control boundary around which a publisher can express, automate, monitor, and eventually verify a retention policy. Kubo still performs the actual pin and repository operations.

The publisher guide now distinguishes pointer publication from content retention and lists the pins, MFS references, watched-IPNS policies, archives, remote pinning services, and garbage collection that a complete implementation must consider.

Expands browser fallback documentation

The docs now recognize the TGP root as a useful user-facing location, not merely a JSON holder. They describe how a browser helper may:

• detect an IPFS-aware browser environment
• navigate directly to the current CID
• try a configured Web2 destination
• use a gateway or redirect document
• provide recovery links when automatic navigation is blocked

Scope

This PR is documentation-only.

It intentionally does not change:

• TgpTemplates
• the currently generated runtime legal.md
• the currently generated legal JSON property
• PublishQueue
• pinning, unpinning, garbage collection, or retention behavior

The generated runtime notice and the previously identified publish-retention question should be reviewed separately after this documentation correction is approved, so protocol/runtime behavior is not silently mixed into a docs PR.

Diff

• 1 commit
• 9 files changed
• 2 obsolete legal pages removed
• no application or publishing behavior changed